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Ruoysun

Premier King Size Mattress 12 Inch, Medium Firm Hybrid Mattress in a Box

  • Based on 17 reviews
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Availability: 20 left in stock
Fulfilled by Amazon
Arrives Tuesday, Sep 22
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Color: Grey


Size: King (U.S. Standard)


Set name: 12" Medium Firm


Features

  • Precision-engineered for spinal alignment: Our 7-zone pocket springs are designed to follow your body's natural curve shoulders gently cushion, the lower back receives targeted support, and legs rest in complete relaxation. A plush memory foam layer sits on top, adding just enough softness. The result is a medium-firm feel that works very well for back, side, and stomach sleepers.
  • Effective motion isolation for restful sleep: With over 600 individually encased pocket springs, movement is largely isolated at its source. When sharing your king bed with a partner or a pet, you'll notice very little motion transfer minimal shaking, very low noise, and barely any vibration. Even light sleepers can enjoy deeper, more uninterrupted rest.
  • Cooling comfort that lasts all night: Heat buildup doesn't have to ruin your sleep. Our 7-layer construction includes a cooling-gel memory foam layer and ventilated comfort foams that actively pull heat and moisture away from your body. Combined with a breathable, soft knit cover, you'll remain cool, dry, and comfortable through the night helping you avoid waking up hot and sweaty.
  • Reinforced edge support you can rely on: We've reinforced the entire perimeter of this king size mattress with three full rows of high-density springs that's 30% more structural support than standard designs. Sit on the edge to put on socks, lie near the side, or lounge comfortably anywhere. The surface stays firm and supportive from edge to edge, night after night.
  • Easy setup: Each Ruoysun king mattress in a box is compressed and rolled into a compact box that fits easily through doorways and up stairs. Simply unbox, unroll, and let it expand (allow 4872 hours to reach full shape). Built in our own factory with multi-stage quality inspections, CertiPUR-US certified materials, and fiberglass-free construction. Backed by a 10-year limited warranty.

Description

My partner and I have different sleep schedules. If one of us gets up or tosses at night, will it wake the other up? That’s a key benefit of hybrid mattresses. Each pocket spring works independently, conforming to your body and absorbing most motion, which helps reduce disturbance. I’m a side/stomach/back sleeper. Is this mattress suitable for me? Hybrid mattresses are designed to work well for different sleep positions. We recommend a medium-firm model (firmness level 5–7.5) which suits most sleep positions and body weights. I sleep hot. Will this mattress trap heat and make me sweat? The pocket spring structure of a hybrid mattress offers good breathability. Gaps between springs create natural air channels for heat and moisture dissipation. Is the mattress made of safe materials? Will it have a strong chemical smell? It's made with safe materials. You may notice a faint material smell upon unboxing, which typically dissipates significantly within a few hours in a ventilated area. I’m confused between Pillow Top and Euro Top. Which one is right for me? It really comes down to comfort and how you plan to use the mattress. Our EURO TOP is for you if: You want a balanced sleep—soft and supportive without that “stuck-in” feeling. It offers a more durable, luxurious feel, similar to high-end hotel beds. 12 Inch King Mattress 12 Inch Cal King Mattress 14 Inch King Mattress 12 Inch King Mattress 14 Inch King Mattress Welcome to Ruoysun! As a specialized mattress manufacturer dedicated to excellence, we create high-performance sleep systems designed to elevate your rest experience. We recognize that quality sleep forms the foundation of wellness. Every mattress is engineered with precision, combining ergonomic support and comfort to deliver truly restorative sleep. Embark on a journey of exploring wonderful sleep with Ruoysun! The perfect morning starts with Ruoysun hybrid gel memory foam mattress. Designed with motion isolation to minimize sleep disruptions, absorbing noise and vibrations so your partner can rest peacefully.

Brand: Ruoysun


Size: King (U.S. Standard)


Product Dimensions: 80"L x 76"W x 12"Th


Item Weight: 72 pounds


Item Firmness Description: Medium Firm


Top Style: Euro Top


Cover Material: Skin-friendly Fabrics


Number of Layers: 7


Fill Material: Gel Memory Foam, High Density Foam


Weight Limit: 950 pounds


Item Firmness Description: Medium Firm


Number of Layers: 7


Weight Capacity Maximum: 950 pounds


Additional Features: Breathable, Durable, Edge Support, Low Motion Transfer, Pressure Relief


Mattress Coil Type: Pocketed Coil


Construction Type: Hybrid


Number of Mattress Coils: 600


Size: King (U.S. Standard)


Item Dimensions L x W x Thickness: 80"L x 76"W x 12"Th


Item Weight: 72 pounds


Item Thickness: 12 inches


Item Depth: 12 inches


Item Dimensions: 80 x 76 x 12 inches


Cover Material: Skin-friendly Fabrics


Fill Material: Gel Memory Foam, High Density Foam


Product Care Instructions: Spot Clean Only


Mattress Comfort Layer Material: Comfort Foam, Gel Memory Foam


Material Type: Foam, Gel Foam, Memory Foam, Pocket Springs, Skin-friendly Fabrics


Brand Name: Ruoysun


Model Name: King Size Mattress


Product Benefits: Back Pain Relief, Improves Sleep, Pressure Relief, Reduces Toss & Turn, Stress Relief


Model Number: King Size Mattress 12 Inch


Number of Items: 1


Mattress Type: Standard Mattress


Manufacturer: Ruoysun


Unit Count: 1 Count


Included Components: King Size Mattress


Manufacturer Part Number: RUO12K


Set Name: 12" Medium Firm


top-style: Euro Top


Color: Grey


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Sep 22

Yes, absolutely! You may return this product for a full refund within 90 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • Good quality and good price.
This is Ruoysun Full Size Mattress, Medium Firm Full Bed Mattress in a Box, Hybrid Construction Individual Pocket Springs with Gel Memory Foam, Pressure & Back Pain Relief, CertiPUR-US. This is a full size mattress that come in a box. The mattress is of good quality. I unboxed and took off the plastic. The instructions say it can take 72 to expand. It was 80% inflated in an hour and 100% the next day. The memory foam on top is good. It is a little on the softer side. This says "Medium-Firm" and that is about right. I think I like a firmer mattress, but that is just my preference. The mattress is just a described. The quality of the build is good. I like the hybrid construction with the coils on the bottom. The mattress comes with a mattress cover as well which is nice. It even comes pre-installed on the mattress. I have slept on this for several nights now and I do like it. I switched from a coil mattress. The memory foam mattress sleeps "hot". The mattress traps more heat next to your body than a traditional mattress. This can be good or bad depending on your preference. Overall, this is a really good quality mattress at a good price! ... show more
Reviewed in the United States on April 9, 2025 by DrHelper
    • Nice mattress for average weight people.
For starters, I'm 330lbs and 6ft 4, and this is a bit *too* soft for me. But that's expected as people over 250lbs tend to perceive mattresses as softer since they depress more under our added weight. That said, I'd put it on the softer end of medium, where someone who is of average weight would probably put it at the higher end, and someone super skinny would think it's firm. Hope that helps! For me, I need firm, but for an average person, this will be exactly what it says it is and I think the feel of it is wonderful. Just not for long term use if you're REALLY big like me. Oh, and it only took a few hours to expand, and there were no weird smells once it did. I have an air quality monitor too that measures VOCs and they only went up 2 parts per million, which for a ton of brand new foam, is quite excellent, and still well within safe healthy ranges. ... show more
Reviewed in the United States on April 20, 2025 by Glass
    • Good
This is a good mattress for the price point. It arrived in a surprisingly small box, but does expand to full size in about a day. It is a great guest room mattress!
Reviewed in the United States on July 22, 2025 by Kevin Grierson
    • Mattress
This mattress is pretty comfortable and gives good support, especially for my back. I like that it stays cool and doesn’t get sweaty during the night. The pocket springs help reduce noise and I don’t get disturbed when my partner moves. The edge support is strong, so I don’t feel like I’ll roll off. The only downside is it took a couple of days to fully expand after unboxing, which was a bit annoying. Overall, a good mattress for the price. ... show more
Reviewed in the United States on June 30, 2025 by Reviewer
    • Nice medium firm hybrid mattress
This is a nice and affordable medium firm hybrid mattress made from decent materials and I'm finding it comfortable to sleep on. It definitely leans more to the firm side which is perfect for me. I gave it plenty of time to regain its shape after removing the compression wrap (about 48 hours), and there wasn't a great deal of off gassing from the foam. The sides do not sag when you sit on the edge of the bed and I don't feel like this mattress builds up any heat while you sleep. As for the durability only time will tell but this bed seems well made and sewn. ... show more
Reviewed in the United States on April 29, 2025 by Daisy Doolittle
    • Amazing Amazing OMG Amazing!
This bed is perfect! It's is springy without being too soft. It feels amazing to sleep on. The height is perfect (I placed it on top of the box springs I already owned). It perfectly fits standard full size mattress covers and sheets. It's so very comfortable and the quality is amazing! It's been about 3 weeks and I'm still having about it. I'll definitely update my review in a few months but the quality is so worth the price! ... show more
Reviewed in the United States on April 21, 2025 by Elle L.
    • Comfortable and Good Value
This Ruoysun mattress has been great so far. It came compressed but fluffed up fast and was ready to sleep on right away. It has a comfortable feel—firm enough but still has some give—and it’s held shape with no weird dips or edges after several nights. I’ve used it with and without a box spring just to test things out, and it worked fine both ways. No weird smells, no issues with setup, and it feels like a good value for the price. The sleep has been great—way better than our last setup. I didn’t expect much for this price but I’ve got zero complaints and I’d order it again if I needed a second one. Worth it for the comfort alone. ... show more
Reviewed in the United States on April 22, 2025 by Jamie
    • No More Musical Beds
Getting a new mattress around here is practically an event, everyone immediately jumps on it to test it out. This hybrid mattress had the whole family giving their two cents: the kids loved the bounce from the pocket springs (perfect for jumping, they say), while the grown-ups appreciated the comfy-but-not-too-soft gel memory foam top layer. It's supportive enough to handle creaky backs and busy bodies without feeling like you're sinking in quicksand. The edge support means fewer accidental roll-offs for little ones who sneak in during the night, and the medium firmness seems just right for keeping everyone happy. The fact that it came rolled up in a box made it a lot easier to maneuver upstairs without calling a family meeting first. Seems like a good pick for a family who values a decent night's sleep. ... show more
Reviewed in the United States on April 13, 2025 by Levia B.

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