An all-foam mattress made for all sleepers. The Prime is the world's first all foam mattress with four levels of firmness in one. Produced with high-density materials with a unique four-layer contouring structure, the Prime features SweetNight's Contouring Curveâ„¢ design to give sleepers the ability to choose the firmness profile that suits their sleep needs. Physically flipping or rotating the mattress 180 degrees changes between comfort zones and firmness to suit different sleep positions.