We looked for mattresses with minimum memory-foam density of 3 pounds per cubic foot and a minimum ... should seek memory foam with densities of 4 to 5 pounds per cubic foot and polyfoam that ...

The flippable bed offers a firmer comfort layer on one side of the mattress, with a suggested age range of 3 to 7, and a softer memory foam layer on the other side that’s suggested for ages 8 ...

Though Purple has discontinued the Purple Hybrid and Premier mattresses ... The Purple 3 has a 3-inch layer of Hyper-Elastic Polymer at the top, while Purple 4 has 4 inches.