Amazon Basics 9inches Bi-Fold Box Spring, Mattress Foundation, Easy to Assemble, Cal King

(10 customer reviews)


  • Cal King-size box spring with a removable cover is adaptable for use on a bed frame or platform bed as a mattress foundation (includes box spring only)
  • Fold-in-half design allows for easier maneuvering through tight spaces, like staircases and doorways
  • Durable black steel frame with a poly jacquard removable cover that zips into place
  • Sets up easily in about 30 seconds (no tools required)
  • Product dimensions: 9 inches high
SKU: B08L5DZ26Y Category:


Product Description

Amazon Basics 9inches Bi-Fold Box Spring Mattress Foundation with Removable cover, Easy to Assemble, Cal King

From the Manufacturer

Amazon Basics

From the manufacturer

Amazon Basics

9-Inch Box Spring

9-Inch Box Spring

This 9-inch box spring provides added height and a strong, sturdy foundation for a mattress. By reducing impact, it can promote longer mattress life.

Compact Bi-Fold Design

Compact Bi-Fold Design

With its compact folded-in-half design, the box spring maneuvers easily around tight spaces, like up and down staircases and through doorways.

Durable Steel, Easy Set-Up

Durable Steel, Easy Set-Up

The sturdy box spring’s black steel frame provides reliable strength. For quick set-up, simply unfold, and it snaps into place (no tools needed).

Cover Included

Cover Included

The included fabric cover slips effortlessly over the box spring and zips securely shut.

Amazon Basics

Amazon Basics

Additional information

Weight 52.4 lbs
Dimensions 83 × 71 × 9 in
Item Weight

52.4 pounds

Product Dimensions

83 x 71 x 9 inches

Country of Origin


Item model number



52.37 Pounds



Date First Available

June 16 2021


Amazon Basics

10 reviews for Amazon Basics 9inches Bi-Fold Box Spring, Mattress Foundation, Easy to Assemble, Cal King

  1. ALICE T

    Great product for hard to reach placesEasy set up and functions like a regular box spring. May be a skosh smaller than a regular size box spring but doesn’t affect my life whatsoever. Couldn’t get a queen boxspring down our basement. We tried a platform frame Didn’t like it. This one is great

  2. Airica B

    Life Saver!Imagine it’s moving day & the last thing the movers unload off the truck is the Queen bed set that you recently purchased only to find that the box spring WON’T clear the stairway! After all of the work that it took to pack & move, that’s real heart 💔! This was my recent issue. After parking my old school box spring on the living room wall, I searched Amazon for 1 that could navigate it’s way up my narrow staircase.This modernized, quad folding box spring was just what I needed to get my mattress off of the floor! My teenage daughter & I were able to carry it upstairs. It assembled with ease in minutes! Simply unfolded it, added the cover & Voíla! #ProblemSolved #SleepsGreat #WorthIt

  3. Michael Mohr

    Outstanding value!Outstanding value!

  4. Vickie

    Didn’t fit my bed frameDidn’t fit my bed frame

  5. Keket

    Easy set upI was skeptical about these. I have never had a metal box spring. They have always been wooden. These arrived in one box. They are able to be folded and compressed to not take up so much room. They would be easy to store should you need to. The metal is steel and it is durable and does not feel as though it will bend easily. It does feel more sturdier than the wooden ones. They did come with a cloth cover. The cover is on the box spring while in the box but you have to unfold it and put the rest of the cover on the box spring. Then it zips up. There are also directional tags that will tell you top from bottom. It is super easy to assemble and the cover is also easy to put on. I like that the covers can be removed to be washed if needed. I do wish the cover would come in other colors. These fit nicely on my new king bed frame. My mattress hangs over maybe a half inch on each side. I don’t know if this is the mattress being overly big or the box springs being a little smaller. Both are kings.

  6. MyOhMy

    Fits into a small spaceI have a small place but get a lot of company. I don’t have room to house so many people at a time so this has come in very handy. I have a guest room but that tends to get filled. This allow someone to ‘camp’ out in my office with a real bed. I’ve got a padded mattress that rolls up that goes on top and so far no complaints but that may be because I’ll kick out complaining freeloaders. I like that I can accommodate my friends and family and that it doesn’t take all my room to store this when they aren’t around.

  7. Susan Hale Dake

    Amazon Basics 9inches Quad-Fold Box SpringEasy to assemble and made well. It’s sturdy and holds a good amount of weight. Would recommend.

  8. TK

    quite and studyI like this 9 inch bi fold box spring, worked great to replace my old one. quite and study dont make any noise why people lay on it. It arrives folded and flat packed in an box, but there is no need for assemble. just unfold and extend. very simple. but i think the price little high for just an box spirng

  9. Melrel05

    Works even better than I imaginedI’ll admit I was hesitant and definitely had my doubts when it comes to this Amazon Basics Quad-fold box spring. I mean how well could a metal box spring be? There has to be a reason why they made them the way they did for the last probably over 100 years right?Surprisingly this actually works better than any other box spring I ever had, and there’s numerous reasons why. It’s steel so it’s super sturdy, honestly more sturdy than a traditional wooden one. since this is metal it’s much less likely to need replaced ever. And considering you can actually take the cover off of this one and wash it you don’t have to worry about the box spring becoming gross either. Since this frame can easily be taken apart and then put back together there is no hassle moving it to another room or house, or even another state.And speaking of that, setup wasn’t very hard at all. It says you should have 2 people, but I did it myself just fine. The only part I had a hard time with was getting it on the bed frame. The whole process only took me about a half an hour. It wouldn’t be difficult to take back a part either, probably even less time. Overall super happy with this and completely 100% recommend this!

  10. Nathan

    Works exactly as expectedI’ve been using this for a few weeks and it’s worked exactly as expected with no issues. I wanted a very low bed but didn’t want to be on the floor, and I wanted something a bit sturdier than a low profile bedframe. Looking back on costs though, I feel like a bed frame would’ve worked just as well and saved some money.But for what this is and what they go for (more expensive than I would think) this does a good job, value wise, so I can recommend it.

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