Polyester FEATURES - This sheet is made of 100% cotton, this cozy flannel sheet set features a charming Grey Solid, soft and subtle hues to create an enjoyable look. Also provides warmth and a fun style for your bedroom FLANNEL - It is known for its softness, warmth, and affordability. When it comes to extra warmth, flannel is the clear winner. It also use a GSM weight indicator rather than thread count to measure quality. It uses 160 GSM for more warmth and better quality FIT - With elastic all around, snugly with your mattress. Fits mattress up to 12 inches deep PACKAGE INCLUDES AND MEASUREMENT - 1 Flat Sheet: 66(W) inches x 96(L) inches, 1 Standard Pillowcase: 20(W) inch x 30(L) inch, 1 Fitted Sheet: 39(W) inches x75(L) inches+12 inches depth EASY CARE - Machine washable and dries quickly on tumble dry low. Do not bleach