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Zinus

Zinus 9 Inch Twin WonderBox(TM) Smart Box Spring, Quick Assembly Mattress Foundation, Durable Metal Frame, Grey

  • Based on 18,504 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Monday, Jun 15
Order within 18 hours and 58 minutes
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Size: Twin


Style: 9 inch


Pattern Name: New Quick Assembly


Features

  • EASY DELIVERY & A CLEANER PLANET Delivered in our earth-friendly WonderBox that is surprisingly small and easy to maneuver through doorways and tight corners.
  • EFFORTLESS ASSEMBLY - Tool-free design snaps together in minutes for a frustration-free setup.
  • CUSTOMIZABLE COMFORT - Choose from two heights to create your perfect sleep oasis 5 inches for a lower profile, or 9 inches for an extra boost.
  • DURABLE STEEL CONSTRUCTION - Provides long-lasting support for your mattress, maximizing comfort and lifespan.
  • WORRY-FREE WARRANTY Sleep soundly with an included 5-year warranty.

Description

As the backbone for solid mattress support, a box spring that falls short can make or break your night’s sleep. We developed the Smart BoxSpring® with unbeatable durability and rock-solid stability to keep your mattress in shape for years to come. And our latest quick assembly version gives you total confidence when it comes to setup, requiring fewer bolts and ingeniously designed with easy to use, tool-free brackets. With our simple, step-by-step instructions on hand, you’ll have this foundation built and ready to use within minutes. Built with a strong and durable steel frame and a versatile poly jacquard cover that slips right on, the Smart BoxSpring® is the picture of dependability for any mattress. All packed in a compact shipping box with everything included, even our 5-year worry free warranty! Now that’s peace of mind you can sleep on.

Size: Twin


Material: Alloy Steel


Product Dimensions: 73.8"L x 37.9"W x 9"H


Style: 9 inch


Special Feature: Easy assembly, Squeak Resistant


Other Special Features of the Product: Easy assembly, Squeak Resistant


Included Components: Box Spring, Installation Manual


Brand Name: Zinus


Manufacturer: Zinus


UPC: 841550372694


Global Trade Identification Number: 94


Manufacturer Part Number: ZU-FBSSG1OC-09T


Model Number: ZU-FBSSG1OC-09T


Item Type Name: Quick Assembly Mattress Foundation, Durable Metal Frame


Material Type: Alloy Steel


Required Assembly: Yes


Assembly Instructions Description: Included


Style Name: 9 inch


Color: Grey


Finish Types: Unfinished


Furniture Finish: Gray


Form Factor: Standard Box Spring


Shape: Rectangular


Compatible With Mattress Size: Twin


Maximum Weight Recommendation: 350 Pounds


Size: Twin


Item Dimensions L x W x H: 73.8"L x 37.9"W x 9"H


Item Weight: 9.22 Kilograms


Item Dimensions: 73.8 x 37.9 x 9 inches


Item Depth: 73.8 inches


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Jun 15

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

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Similar Products

Top Amazon Reviews

    • Very sturdy and surprisingly quiet
Size: King Style: 9 inch Pattern Name: New Quick Assembly
I’m honestly impressed with this foundation. I bought the king size and was expecting it to be heavy and complicated, but it was actually very easy to put together. The frame feels solid once it’s assembled, and it doesn’t wobble or shift when you get in and out of bed. What I like the most is that it makes absolutely no noise. No squeaks, no movement sounds at all. The support is firm in a good way, and the surface feels steady under the mattress. It also doesn’t weigh as much as I expected, so moving it around wasn’t a problem. Overall, it looks clean, feels durable, and holds the mattress perfectly without sliding. The height is perfect to match the regular bed headboard. (4 " works )Great buy. ... show more
Reviewed in the United States on November 19, 2025 by Amaris23
    • Best Purchase Ever
Size: Queen Style: 5 inch Pattern Name: New Quick Assembly
I never write product reviews, but this was such an awesome purchase. This is the BEST box spring I have ever owned. If you’re on the fence about buying this product, or you’re trying to decide between options, here’s a number of reasons to go with this one. 1. Noise Level: NONE. Completely silent. This was my #1 reason for wanting a new box spring in the first place, and it does not disappoint. Our previous box spring (the traditional wood/spring kind) had become squeaky over the years, and kept waking up our 5 month old baby. This new box spring hasn’t made one tiny noise since day one - our baby has been sleeping through the night. Relief is an understatement. 2. Sturdiness: I have never felt so supported by my bed. It feels even better than when our previous box spring was brand new, so I know it’s not just because it’s new. I have chronic shoulder pain, and while a new box spring obviously isn’t a cure, I have been waking up significantly less sore for the first time in years. My husband doesn’t have the same pain issues, but he agrees that our bed feels much more sturdy and comfortable, because our bodies are better supported. 3. Assembly: So easy. I am not in my greatest shape (I did just have a baby), but I was able to put it together without my husband’s help. The box comes with some screws and an Alan key, and that’s honestly all that’s needed. The directions are pretty easy to follow. I will say that the “Up” stickers were placed on the parts in a way that was a little confusing at times, but if you pay close attention to the pictures in the instructions, you’ll be fine. It took me less than an hour. I cannot recommend this box spring enough. Do yourselves a favor and purchase this. You can thank me later. :) ... show more
Reviewed in the United States on February 11, 2025 by cnelson1102
    • Terrible construction and won’t stay put together.
Size: Queen Style: 5 inch Pattern Name: New Quick Assembly
Review Image by Gillian Murphy
Review Image by Gillian Murphy
Review Image by Gillian Murphy
If I could give this zero stars I would. Not particularly easy to assemble since everything came unlabeled, the directions just a couple pictures, but I figured it out. Purchased it to make my new bed firmer which it did do! But it does slide around a bit, annoying but again no big deal, I would just slide it back in place and planned on putting down rubber strips or something to help it grip. The issue: Occasionally when rolling over I heard a pop and worried something was breaking and woke up today with the corner of my mattress sinking. I pulled the bed off and realized a lot of the slats had come loose and the bed was sinking inside the frame. The slats aren’t long enough to meet all the way inside their little holders and every time the frame shifts they pop out of place. The four outside sides aren’t screwed in so they can be pulled slightly apart and they just pop right out. Seems like it wouldn’t be a big deal, but since it slides around on my frame it keeps popping out. Also the plastic joints holding the two middle pieces together have a small plastic piece holding it on, so no matter how you place it the weight of the mattress slightly off the frame pops it out of place and that is also contributing to the issue with the slats. Seems dangerous and bad for your mattress. I’m super frustrated with how this turned out and now I’m going to have figure out how to disassemble the whole thing and return it somehow. See pictures for a better explanation. ... show more
Reviewed in the United States on May 22, 2025 by Gillian Murphy
    • Straightforward assembly, solid once together
Size: Full Style: 7 inch Pattern Name: New Quick Assembly
After putting this boxspring together, I don't think I'll ever purchase a pre-assembled one ever again! Assembly was pretty easy, and the box has everything you need, including an allen wrench and a small ratchet. The instructions were specific about what order to do things in, but I just laid the parts out on my floor in their correct position, and snapped them together as I worked my way around. The powdercoating on the pieces feels high quality, and I did not notice a single sharp edge or corner. The pieces are all light but quite sturdy. I wanted a solid surface for a memory foam bed, and this seems to fit the bill. Something that worried me a little was whether the metal pieces would clank against each other when everything was assembled, but I think it'll be nice and quiet. The only place that metal could touch metal, there's a thin foam pad to prevent noise. At first I thought the cover was slightly undersized, but after getting all of the corners on, the material on the edges curves up over the top just a little on each side. It looks very nice once the mattress is in place. The ease of breaking this down to move it is a huge selling point. I don't plan on moving again in my life, but a large boxspring is a PAIN to move up and down stairs. This breaks down into a small enough package that you could easily move it up a spiral staircase. I would definitely recommend this to anyone who wants a sturdy base for their mattress, and especially to someone who has a tight pathway to their bedroom. ... show more
Reviewed in the United States on April 28, 2023 by Sarah

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