King 12 Inch Memory Foam Mattress in a Box - Cooling Knit Cover

In this review of the King 12 Inch Memory Foam Mattress in a Box, the bottom line is simple: this mattress is best for sleepers who want firm, reliable support with effective temperature regulation. The reviewer found it particularly helpful for those with lower back or hip pain because the layers of memory foam cradle pressure points while the cooling knit fabric stays cool-to-the-touch. Setup is straightforward and the mattress expands within about 12 hours, making it a practical option for people who need a fast, low-fuss refresh to their sleep surface.

Key Features

• Cooling Knit Fabric Cover: The breathable cover helps move heat away from the body so sleepers feel cooler throughout the night.
• Three-layer memory foam: Layered foam construction cradles the body to reduce tossing and turning and to relieve common pressure points.
• Copper memory foam: The copper-infused layer provides a responsive, cradling feel that improves support without feeling overly soft.
• CertiPUR-US & Oeko-Tex certified: Independent certifications mean the mattress foams and fabrics were evaluated to be free from many harmful substances.
• Easy setup: The mattress ships compressed in a box and regains its shape after about 12 hours, making installation quick on most frames or platforms.
• 10-year limited warranty: The warranty provides added confidence for long-term daily use and normal wear.

Who It's For

This mattress is well suited to back and stomach sleepers who prefer a firmer, supportive feel that keeps the spine aligned. Shoppers who value temperature regulation will appreciate the cool-to-the-touch knit cover and breathable construction. Couples who need a balanced mix of support and pressure relief may also find it a good match.

Those who prefer a plush, sinking memory foam experience or who require very soft cushioning for shoulder pressure should look elsewhere. Also, customers who expect a trial return after opening should note this mattress cannot be returned once opened, although it carries a 10-year limited warranty for defects.

Pros & Cons

Pros

• Firm and supportive feel that reduces hip and back pain for many users.
• Cooling knit fabric and breathable layers help with temperature regulation through the night.
• Certifications from CertiPUR-US and Oeko-Tex provide reassurance about harmful substances.
• Easy setup from a boxed delivery and a decade-long limited warranty.

Cons

• Firmness may be too strong for side sleepers who need more contouring at the shoulders.
• Cannot be returned after opening, so buyers should be certain of fit and feel before unboxing.

Specifications

Size	King 76 x 80 in
Profile	12 in total thickness
Cover	Cooling knit fabric cover, breathable and cool-to-the-touch
Construction	3-layer memory foam with copper memory foam layer
Certifications	CertiPUR-US and Oeko-Tex Standard 100 certified
Warranty	10-year limited warranty
Origin	Made in the USA of US foam and global materials

Our Verdict

The King 12 Inch Memory Foam Mattress is a solid choice for sleepers seeking a firmer, supportive mattress with effective temperature control and reputable certifications. It delivers good back support and pressure relief for many users and is good value for those who prioritize a cool, stable sleeping surface and a simple boxed setup.

Frequently Asked Questions

How long does the mattress take to expand?
The mattress typically regains its full shape within about 12 hours after unboxing, though it may continue to off-gas mildly for a short time.

Will the mattress fit adjustable bed frames?
Yes, the mattress can be used on adjustable beds, box springs, slatted platforms, foundations, and directly on the floor.

Is the foam certified for safety?
Yes, the foams and fabrics carry CertiPUR-US and Oeko-Tex Standard 100 certifications indicating independent evaluation for certain harmful substances.