Our YELLOW level is the thinnest pillow. It is designed primarily for small children, stomach sleepers or petite woman.Our WHITE level is recommended for most woman and teenagers with average shoulders who sleep on their side, back or combination. It may also be recommended for a man with narrow shoulders who sleeps on his back primarily.Our GREEN level is recommended for average shouldered man who sleep side, back or combinations. It may also be recommended for broad shouldered woman who sleeps mostly on their side.Contents:1 x MyPillow Premium Twin Pack