Sweetnight King Size Mattress - 12 Inch Memory Foam Mattress in a Box with Pressure Relief, Motion Isolation, CertiPUR-US Certified, Plush King Bed

Product Overview

The Sweetnight mattress measures 79.92 inches long by 75.98 inches wide with a 12-inch thickness, fitting standard king-size bed frames. It weighs 57.1 pounds, making it manageable for two people to position. The construction includes four layers: a breathable fabric cover, comfort foam, wave-cut foam for heat dissipation, and high-density support foam with AirSquare technology. Materials are primarily memory foam with a cotton or polyester cover. The plush firmness level is designed for pressure relief and body contouring. It is not customizable, foldable, or portable once expanded. Setup involves unboxing the vacuum-sealed mattress and allowing 24-72 hours for full expansion at room temperature. Higher temperatures may speed up expansion while lower temperatures slow it down. The mattress accommodates adults and is compatible with various bed frames including platform bases, slatted frames, and adjustable bases. Care typically involves using a mattress protector and spot cleaning the cover. Some reviewers note the mattress expanded fully and provided immediate comfort, while one reported incomplete expansion after three days. The model number is SN-B-M01901-12-K-N1.

Design & Build

The Sweetnight mattress features a 12-inch profile with four distinct layers. The top layer is a breathable fabric cover made of cotton or polyester, providing a soft surface that feels cool to the touch. Beneath this, a comfort foam layer offers initial plushness and pressure relief. The third layer consists of wave-cut foam designed to channel heat away from the body, enhancing breathability. The base layer is a high-density support foam with AirSquare technology, which incorporates extra air spaces to improve airflow and reduce heat retention. This layer also includes reinforced edges to prevent compression when sitting on the sides. The mattress uses memory foam as the primary material, known for its contouring properties. All foams are CertiPUR-US certified, ensuring they are free from heavy metals, formaldehyde, and harmful flame retardants. The OEKO-TEX certification adds another layer of material safety assurance. The construction is non-customizable and not intended for folding or portability after expansion.

Aesthetics are minimalistic with a simple cover design, focusing on function over ornate details. The mattress arrives in a compact box, vacuum-sealed to reduce shipping size. Setup involves placing the rolled mattress on your bed frame, cutting the plastic wrap, and allowing it to expand. The manufacturer recommends waiting 24-72 hours for full expansion, though some reviewers report it may take longer in cooler environments. Cleaning is straightforward: use a mattress protector to guard against spills and stains, and spot clean the cover with mild detergent if needed. The reinforced edges contribute to durability by resisting sagging, a common issue in cheaper foam mattresses. However, one reviewer noted incomplete expansion, with corners remaining only 2.5 inches high after three days, suggesting potential quality control variability. Overall, the design prioritizes cooling, support, and ease of installation for the average consumer.

Performance

In terms of comfort and support, the Sweetnight mattress aims to balance plushness with stability. The memory foam layers contour to the body, providing pressure relief for shoulders, hips, and back. Reviewers who had positive experiences mention excellent support in all the right places, responsive material, and a cool sleeping surface. The motion isolation is effective, reducing disturbances when a partner moves. The plush firmness is suitable for side sleepers who need cushioning for pressure points and back/stomach sleepers who prefer a softer feel. The reinforced edges help maintain a usable sleeping surface edge-to-edge, though long-term durability of this feature is untested in available reviews. Temperature regulation is a key performance aspect: the wave-cut foam and AirSquare design work to dissipate heat, with some users reporting the mattress stayed cool throughout the night. However, as with all memory foam, there is a potential for heat retention if the room is warm or if the sleeper runs hot.

Durability and expansion reliability show mixed results. One reviewer reported the mattress expanded fully and provided immediate comfort, describing it as very strong with no off-gassing odor. Another praised it for offering the best night of sleep in ages. Conversely, a negative review indicated the mattress only expanded to 2.5 inches in the corners after three days, far short of the advertised 12 inches. This suggests possible inconsistencies in manufacturing or packaging. The mattress is relatively heavy at 57.1 pounds, which may make repositioning difficult for some users. It fits standard king bed frames but may be too thick for some low-profile foundations. There are no specific claims about temperature retention beyond the cooling features. The 10-year warranty and 100-night trial provide performance assurances, but the low overall review rating of 2.5 stars indicates potential risks. Users should monitor expansion closely and contact customer service if issues arise.