The T1CMU is a Protection Level 1 tennis mini crew sock designed for those who prefer a thin product and wear narrow lasted shoes. If this product does not give your feet the protection you require, you need to choose a Protection Level 2 Thorlo sock. If you want the most protection available today, you should choose a Protection Level 3 Thorlo sock.
MEDIUM FITS SHOE SIZE: Mens US 5.5-8.5, Womens US 6.5-10.0
LARGE FITS SHOE SIZE: Mens US 9.0-12.5, Womens US 10.5-13.0