Mainstays 8 in Pocket Spring Hybrid Mattress in a Box, Medium Firm, King
Mainstays 8 in Pocket Spring Hybrid Mattress in a Box, Medium Firm, King
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Mainstays

Mainstays 8 in Pocket Spring Hybrid Mattress in a Box, Medium Firm, King

|422 ratings
Mainstays 8 in Pocket Spring Hybrid Mattress in a Box, Medium Firm, KingMainstays 8 in Pocket Spring Hybrid Mattress in a Box Medium Firm KingMainstays 8 in Pocket Spring Hybrid Mattress in a Box Medium Firm QueenMainstays 8 in Pocket Spring Hybrid Mattress in a Box Medium Firm TwinMainstays 8 in Pocket Spring Hybrid Mattress in a Box Medium Firm Full
Bed SizeKing

Key item features

  • Balanced Hybrid Feel: This 8-inch hybrid mattress offers a medium-firm feel, combining a soft quilted cover, 1 inch of support foam, and 7 inches of individually wrapped pocket coils for balanced comfort and support.
  • Minimized Motion Transfer: Individually wrapped steel springs and pocketed coils significantly reduce motion transfer, promoting undisturbed sleep.
  • Secure Mattress Placement: A tight-top design with a non-slip base helps keep the mattress securely in place on your bed frame.
  • King Size Specifications: Measures 76" W x 80" D x 8" H (Full size) and supports up to 500 pounds.
  • Durable Material Construction: Constructed from polyester, steel for wrapped coils, and foam materials for a robust structure.
  • Convenient Boxed Delivery: Delivered as a compressed, rolled mattress-in-a-box, simplifying transport and setup in various rooms.
  • Adaptive Sleep Comfort: Medium-firm comfort suits back, side, and stomach sleepers, offering versatile support.

Specs

Bed size, KingMattress type, Hybrid MattressesMattress comfort level, MediumMattress thickness, 8 inMattress coil type, PocketedBrand, Mainstays

About this item

Product details

This Mainstays King mattress gives you an 8 in hybrid design with a medium-firm feel and easy mattress-in-a-box convenience. It pairs a soft quilted cover and 1 in support foam with 7 in individually wrapped pocket coils for a balanced feel that combines cushioning with steady support. The pocketed coil design helps minimize motion transfer, so movement on one side is less likely to disturb the other. Its medium-firm comfort works well for back, side, and stomach sleepers, while the compressed, rolled pack makes setup easier to manage in bedrooms, guest rooms, and other spaces.
  • Balanced Hybrid Feel: This 8-inch hybrid mattress offers a medium-firm feel, combining a soft quilted cover, 1 inch of support foam, and 7 inches of individually wrapped pocket coils for balanced comfort and support.
  • Minimized Motion Transfer: Individually wrapped steel springs and pocketed coils significantly reduce motion transfer, promoting undisturbed sleep.
  • Secure Mattress Placement: A tight-top design with a non-slip base helps keep the mattress securely in place on your bed frame.
  • King Size Specifications: Measures 76" W x 80" D x 8" H (Full size) and supports up to 500 pounds.
  • Durable Material Construction: Constructed from polyester, steel for wrapped coils, and foam materials for a robust structure.
  • Convenient Boxed Delivery: Delivered as a compressed, rolled mattress-in-a-box, simplifying transport and setup in various rooms.
  • Adaptive Sleep Comfort: Medium-firm comfort suits back, side, and stomach sleepers, offering versatile support.
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Specifications

Bed size

King

Mattress type

Hybrid Mattresses

Mattress comfort level

Medium

Mattress thickness

8 in

Warranty

Warranty information

1 Year Limited

Customer ratings & reviews

4.4 out of 5 stars
stars
422 ratings202 reviews
Includes global ratings and reviews
How item rating is calculated
  1. 5 stars71% (300)
  2. 4 stars15% (65)
  3. 3 stars4% (16)
  4. 2 stars3% (13)
  5. 1 star7% (28)
Filtered and sorted results would be available on the new 'Customer ratings & reviews' page.
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Showing 1-3 of 202 reviews

Oct 7, 2026
Reviewer name: HannahR
5 out of 5 stars
5 out of 5 stars review

Very comfy

[This review was collected as part of a promotion.] I absolutely love this medium firm hybrid mattress! It is extremely comfortable and I struggle with finding the perfect mattress. It was very easy to unpack move. It is very heavy, however, and you definitely need two people to carry it. The parents is very nice and slick and I love the blue outline. The edges are very nice and you can tell the quality is very durable because of the stitching. Overall, I would highly recommend this mattress if you want to stay in budget, but also have a great product.

Review from sinomax-usa.com
Helpful?42QQ6SD33KQE19485700988
Oct 29, 2026
Reviewer name: YessiS
5 out of 5 stars
5 out of 5 stars review

Very comfortable

[This review was collected as part of a promotion.] Perfectly fine I love it it is very comfort and perfect size por 2 perfect the mattress is very comfortable and nice to sleep 😴 I recommend to try it

Review from sinomax-usa.com
Helpful?42QQ6SD33KQE19485700988
Nov 4, 2026
Reviewer name: CristalR
5 out of 5 stars
5 out of 5 stars review

Affordable matress

[This review was collected as part of a promotion.] If your looking for a Medium Firm Matress this Mainstay 8 is perfect! It is very easy to install. It obtains its shape as soon as you open it from the plastic. Plus the price is such a deal!

Review from sinomax-usa.com
Helpful?42QQ6SD33KQE19485700988
Current price is $218.00
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