Wash with cold water, inside out. Chest to fit(all way round). Slim Fit XS-8 (Chest: 34-36"). Slim Fit S-10 (Chest: 37-39"). Slim Fit M-12 (Chest: 38-40"). Slim Fit L-14 (Chest: 41-43"). Slim Fit XL-16 (Chest: 43-45").