Sunny Heart MAT12 King 8-Inch Medium-Firm Gel Memory Foam Mattress

Medium-Firm: Sunny Heart MAT12 is an 8-inch king memory foam mattress listed as medium firm, with gel memory foam and a high-density foam core. Its boxed, unroll-to-set-up format and removable cover are practical features, while the listing contains inconsistent model and package details worth checking before purchase.

At a glance

The listing describes gel memory foam over a high-density foam core, with medium-firm feel.
The cover is described as removable and machine washable in the feature text.
The mattress ships compressed in a box. The listing says to allow 24–72 hours to regain its intended shape, loft, and feel.

Price

$178.48Save 15%

Reference price: ~~$209.99~~

Price checked: Nov 14, 2026

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Pros and cons

Pros

King size and an 8-inch profile suit buyers seeking a thinner foam mattress.
A removable, machine-washable zippered cover can make cleaning more convenient, according to the listing.
The box format and unroll setup avoid carrying a fully expanded mattress through the home.

Cons

An 8-inch profile may not suit buyers seeking a thicker mattress.

Technical specifications

15 specifications

Identity
Brand	Sunny Heart
Model	MAT12
Size	King
Mattress type	Memory Foam

Dimensions and installation
Dimensions listed	80 x 8 x 76 inches
Thickness	8 inches
Weight listed	52.9 pounds

Construction and feel
Firmness	Medium Firm
Top style	Euro Top
Number of layers	1
Fill material	Gel Memory Foam, High Density Foam
Cover material	Polyester
Color	White

Features and capacity
Additional features	Breathable, Pressure Relief, Removable Cover
Weight limit	1200 pounds

What to know before buying

Listing details to confirm

Listing details conflict or remain unconfirmed: the model is MAT12 in the model fields but the manufacturer part number is MAT20, and the stated dimensions appear in differing orders, including 80"L x 8"W x 76"Th. The feature text describes a soft mattress while the specification says Medium Firm. The explicit contents list says Memory Foam, while a separate highlight claims a mattress with a removable fiberglass-free cover and certification. Verify the selected listing's dimensions, feel, exact model and included items. The listing also says expansion takes 24–72 hours.

What’s in the box

Memory FoamIncluded
Removable fiberglass-free cover and mattressCheck selected pack

Check which accessories are included in your selected pack before buying.

Who is it for?

A good fit for

King-bed shoppers looking for an 8-inch memory foam mattress with a listed medium-firm feel.
Buyers who prefer a mattress delivered compressed and can allow time for it to expand.

Less suited to

Shoppers who need a firmly confirmed model number, exact dimensions or package inventory before ordering.
Buyers seeking a thicker mattress or a feel other than the listed medium-firm option.

Sunny Heart MAT12 King 8-Inch Medium-Firm Gel Memory Foam Mattress · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.8 / 5 · 49 ratings

5 stars84%84%
4 stars9%9%
3 stars7%7%
2 stars0%0%
1 star0%0%

Customer feedback highlights comfort and firmness, and some buyers describe the mattress as good value. Those impressions may matter to shoppers considering its listed medium-firm feel, but the available feedback does not establish that it will suit every sleeper or verify the product specifications. The overall rating distribution is mostly five-star, with some three-star ratings, and the sample is limited.

Positive themes

Customers describe the mattress as comfortable.
Customers appreciate its firmness.
Customers mention value for money.

Frequently asked questions

What size and thickness is this mattress listed as?

It is listed as King and 8 inches thick. The dimensions fields are inconsistent in how they order the measurements, so confirm them in the selected listing.

What is the listed firmness?

The specification lists Medium Firm, although feature copy calls the mattress soft. The actual feel is not independently established, so check the product listing if firmness is important to you.

How long should it take to expand after unboxing?

The listing says to allow 24–72 hours for it to regain its intended shape, loft, and feel.

Is the cover removable and washable?

The feature text describes a removable, machine-washable zippered cover. The exact included cover details should be confirmed because the package information is inconsistent.