100% Polyester ? SIZE GUIDE: This is Asian size, if you are cycling build, please go one size up for slim fit and two size up for loose fit. Professional fitting design, use more breathable material, and according to human body engineering use suitable materials to make it more dry and comfortable.Brand non-slip silicone band design on the bottom of the shorts, it is better to fix short leg to ensure riding satefy and comfortable. Unique mesh fabric under armpit for keeping drying and cooling, Direct-vent panels and full length zipper for ventilation, wide Belt design make more comfortable and not easy to deformation. The collar label adopt heat transfer printing, it is more comfortable to wear, hem with WOSAWE logo silicone band, hold the jersey in place during riding. 3 pockets at the back, easy to carrying your small articles. Reflective strip at the back to ensure night riding safety, 3D cut, quick drying fabric material of the short, to keep you more comfortable and fitness. 4D Gel Pad is designed next to skin, make your ride even more dry and comfortable.