Soft and breathable 100% jersey knit cotton will give your baby a comfortable night's rest. A deep 9 ½" (24 cms) gusset makes for a safe snug fit with any crib mattress. The edges are fully elasticized and finished for extra durability even after lots of washes. Fits standard size crib mattresses 28" x 52" (71 x 132 cms). Machine washable in warm water and low tumble dry.