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Serta Five Star Mattress Tranquility 12-Inch Firm– King– Zoned Support, Pressure Relief, Cooling– Bed-in-a-Box – Ideal for Back & Stomach Sleepers – 100 Night Trial, 10-Year Limited Warranty

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Availability: Only 6 left in stock, order soon!
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Arrives Tuesday, May 19
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Style: Level 3 Firm 12"


Size: King


Features

  • FIRM MATTRESS FOR BACK & STOMACH SLEEPERS: Designed for a supportive, firm feel that helps promote proper spinal alignment and reduces sinkage for a refreshing night's sleep.
  • 3-ZONE TARGETED SUPPORT: Zoned foam targets lumbar and lower back areas for enhanced support and pressure relief.
  • PRESSURE RELIEF FOAM COMFORT: Layers of PillowSoft Aire Foam and QuiltLoft Memory Foam cushion pressure points such as shoulders, hips, and knees. COOLING & BREATHABLE MATTRESS: Breathable fabrics and foams help keep you cool and fresh all night.
  • DURABLE SUPPORT FOR UNDISTURBED SLEEP: Durable coils reduce partner disturbance-provide lasting support across the mattress. BUILT TO LAST CERTIPUR-US CERTIFIED: Sleep soundly - CertiPur-US certified and backed by a 10-year limited warranty.
  • EASY SETUP MATTRESS-IN-A-BOX MADE IN USA: Delivered in a box and made in the USA with global components. Setup takes minutesjust Unbox, Unroll, Unwind.

Description

Sleep better with the Five Star Mattress Tranquility 12-Inch Firm Mattress, designed for cooling comfort, targeted support, and long-lasting durability. This firm mattress is ideal for back and stomach sleepers, providing a stable sleep surface that promotes spinal alignment and helps reduce pressure on shoulders, hips, and knees. The 3-Zone Support System focuses on lumbar support for healthy posture, while advanced memory foam layers offer cushioned comfort and pressure relief. Stay cool with a breathable, airflow-enhancing mattress cover, and enjoy peace of mind knowing all foams are CertiPUR-US certified. Perfect for primary bedrooms, guest rooms, or kids’ rooms, this mattress-in-a-box delivers premium quality at an affordable price, expanding quickly for immediate comfort. 100 Night Trial, 10-Year Limited Warranty

Brand: Serta


Size: King


Product Dimensions: 79.5"L x 76"W x 12"Th


Item Firmness Description: Firm


Top Style: Tight Top


Cover Material: Polyester Blend


Number of Layers: 7


Fill Material: Memory Foam


Special Feature: Breathable, Durable, Low Motion Transfer, Pressure Relief, Temperature Regulating


Color: White


Product Dimensions: 79.5 x 76 x 12 inches


Item Weight: 106.8 pounds


Manufacturer: Serta Simmons Bedding, LLC.


Item model number: 50


Refill: Memory Foam


Care instructions: In order to protect your mattress from stains and spills, we recommend using a mattress protector. This will also help with the overall health and lifespan of your mattress., To clean your mattress, we suggest applying baking soda to the soiled area and letting it stand for about 15 minutes. Then, vacuum and repeat as needed. It's important that you also air the product out as much as possible., We do not recommend applying liquids to the product. Applying liquids may stain the fabric and could potentially make the soiled area worse. Moisture or chemicals applied directly to the mattress can cause premature breakdown of the foam and damage the product.


Assembly required: No


Batteries required: No


Included Components: Mattress


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, May 19

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


  • Worth the purchase
Style: Level 3 Medium 10" Size: Twin
Great sturdy but still soft mattress. We opened it and let it settle for 2 days before putting it on the bed. My kid says it’s very comfortable and has slept like a champ.
Reviewed in the United States on November 14, 2025 by Andrea McCue

  • Nice!! Very comfortable
Style: Level 3 Medium 10" Size: Twin
My daughter loved this mattress!! So I would buy it again.
Reviewed in the United States on January 17, 2026 by Raphael Logato

  • Buy it!
Style: Level 3 Firm 12" Size: Twin
Great quality and comfortable
Reviewed in the United States on January 21, 2026 by Debra

  • Too short, not the normal twin size
Style: Level 2 Medium 8" Size: Twin
This mattress is only 71" long, and the description says it is 74" long. It is unusually short, and it is super disappointing. We always buy Serta, but this mattress is defective. DO NOT buy this mattress. The cheaper brands would be better so that they would at least fit the bed frame. Very disappointing. ... show more
Reviewed in the United States on December 21, 2025 by Bloopfish

  • Size is not big enough
Style: Level 3 Plush 10" Size: Full
My bed is a full size. I measured everything before I bought. This mattress is about 2 inches smaller than it should be all the way around. It is a great mattress but I have to buy wedges to get it to fit.
Reviewed in the United States on November 30, 2025 by Lisel Sipes

  • Amazing mattress!
Style: Level 3 Plush 10" Size: Queen
This mattress is amazing. You can trust serta. Previous to this one I had a serta perfect sleeper mattress which was used for over 10 years. It became too soft but it lasted a long time. Now this one gives me the support my back needs. I was worried the plush mattress would be too soft and not offer support but it is perfect. If you lay flat on it it gives great support and is not hard. I sleep great now. If you want a mattress that isn't too firm but offers support, this is a great choice. It does have a light smell, just like any new mattress would, but once you put sheets on it you can't smell it. And I'm sure the smell eventually goes away. ... show more
Reviewed in the United States on September 10, 2025 by Amazon Customer

  • This feels sooo good ! Your back might need this !
Style: Level 3 Medium 10" Size: Twin
I took a chance and ordered a mattress on amazon... Serta.. good quality brand I know well.. I have now spent exactly 1 night on this mattress so take it for what its worth. * insert happy dance here* My bad back is ecstatically happy ! Awoke with no pain and that feels soooooooo good. The bed in a box was new to me so I was bit nervous about the vacuum seal thing but it was so easy that this 75year old was able to do it alone. I did need some help with the putting it on the bed part but that's why God invented grandsons! Very comfortable , perfect firmness and has the total approval of the dogs. ... show more
Reviewed in the United States on October 11, 2025 by AKSALA

  • Want to buy another
Style: Level 3 Plush 10" Size: Full
Bought this for my daughter and I would like to purchase for myself. It is very comfortable and extremely easy to setup. It is very heavy, so have help bring it inside.
Reviewed in the United States on January 19, 2026 by Rachel

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