SLEEP100 SYN3333042 King 14-Inch Medium-Firm Hybrid Mattress

Medium-Firm: The SLEEP100 SYN3333042 is a 14-inch King hybrid mattress listed as medium firm, with pocket coils, foam comfort layers and a Euro top. Its listed 5-zone support, breathable cover, motion isolation and fiberglass-free construction are manufacturer claims, while customer feedback reports varied experiences with fit.

At a glance

The listing describes targeted 5-zone support for the lower back, shoulders and hips.
Pocket springs and foam are claimed to combine responsive support with reduced motion transfer.
The breathable cover and open pocket-spring construction are described as promoting airflow.
The listing claims fiberglass-free materials and a 365-night home trial, plus a 10-year limited warranty.
Compressed into a box for delivery and setup, according to the listing.

Price

$299.99Save 15%

Reference price: ~~$351.49~~

Price checked: Nov 14, 2026

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Pros and cons

Pros

King dimensions and 14-inch thickness are clearly specified.
The hybrid design combines pocketed coils with a gel-memory-foam comfort layer.
A 365-night trial and 10-year limited warranty are stated in the listing.

Technical specifications

19 specifications

Identity
Brand	SLEEP100
Model	SYN3333042
Size	King
Mattress type	Hybrid
Firmness	Medium Firm

Dimensions and installation
Dimensions listed	80 x 76 x 14 inches
Weight listed	102 pounds
Thickness	14 inches

Construction and materials
Top style	Euro Top
Coil type	Pocketed Coil
Number of coils	384
Number of layers	2
Comfort layer material	Gel Memory Foam
Fill material	Cotton
Cover material	Polyester Blend
Material type	Cotton Blend
Color	Grey

Capacity and features
Weight capacity	800 pounds
Additional feature	Breathable

What to know before buying

Listing details to confirm

The listing identifies the mattress as both cotton-filled and gel-memory-foam comfort layered, and calls its material type a cotton blend. It also lists a 2-layer construction alongside multiple foam and spring elements without explaining the layer breakdown. The title claims fiberglass-free materials and a 365-night trial, while the warranty text specifies a 10-year limited warranty. Confirm material composition, trial terms and warranty conditions for the selected listing.

What’s in the box

Included

Mattress

Who is it for?

A good fit for

King-bed shoppers seeking a 14-inch hybrid with a medium-firm label and pocket coils.
Couples interested in the listing's claimed motion isolation and reinforced edge support.
Back or combination sleepers considering the advertised 5-zone support design.

Less suited to

Shoppers who need independently established evidence of cooling, pressure relief or motion isolation.
Buyers who require fully detailed material and layer specifications before choosing.

SLEEP100 SYN3333042 King 14-Inch Medium-Firm Hybrid Mattress · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.4 / 5 · 1,374 ratings

5 stars72%72%
4 stars13%13%
3 stars5%5%
2 stars2%2%
1 star8%8%

Customer feedback describes the mattress as comfortable and supportive, with favorable reports about firmness, back comfort, sleep quality and setup. Some customers say the fit works well on their bed frame, while others report sheets sliding around. That mixed fit feedback matters for bedding compatibility. These are customer perceptions and do not independently establish the advertised support or motion-isolation performance.

Positive themes

Customers report comfort and a firmness they appreciate.
Feedback mentions support, improved sleep quality and easier setup.

Mixed feedback

Fit feedback is mixed. Some report a good fit on their frame, while others mention sheets sliding around.

Frequently asked questions

What firmness is listed for this mattress?

It is listed as medium firm. The page notes that perceived firmness can vary with body weight and sleep style.

What is the mattress made with?

The listing names pocket coils, a gel-memory-foam comfort layer, cotton fill and a polyester-blend cover. It also calls the material type a cotton blend, so the full material and layer composition is not clearly reconciled.

What trial and warranty are stated?

The listing claims a 365-night home trial and a 10-year limited warranty. Check the selected listing for the applicable terms.

Does the listing state fiberglass-free construction?

Yes. The title and listing text claim fiberglass-free materials. This is a listing claim, not an independently verified material assessment.