"This ultra soft, 100% cotton flannel will keep you warm on cold winter nights. Pointehaven's 5.3 oz (180 GSM) flannel is made from single-ply yarns for soft and durable sheets. Available in a variety of colors and patterns to match every bedroom. The flat sheet is generoulsy oversized and fitted sheet has elastic all around for a snug fit. The pillow cases have european flap closure to have the pillow hidden inside the pillow case. 180 GSM / 5.3 oz cotton flannel is made from single-ply yarns for soft and durable sheet sets 100% Combed Soft Cotton Fitted sheet has elastic all around for a snug fit Fitted sheet fits up to 18"" mattress"