DeFender M2 features an ultra-secure quick release mounting system that adjusts from 25.4 to 34.9 mm, fitting both standard and oversized seat posts. Its two-pivot arm enhances tire coverage and ensures a perfect bike fit. The support frame, made from a stiff engineering-grade polymer, is co-molded with a softer, flexible material at the trailing edge for added durability. The highly polished underside helps prevent dirt buildup and makes cleaning easier.