Wrapping your body in air, the mens S/LAB SPEED tee keeps you feeling cool and dry as you pick up the pace. To help maintain your natural balance, athlete-driven eNosyntex technology helps reduce fatigue and speed up recovery. So, you can give your best. 37.5 Technology optimizes your body's microclimate, to maintain an ideal core temperature so you perform better, longer The Merino wool inserts under the arms are great at managing moisture and odors, as well as making the garment more breathable Weight 100 g Size and Fit Active fit Materials Body: 100% Polyester Body insert: 67% Wool, 33% polyester