Topeak Defender M2For 26" Wheel DeFender M2 has an ultra secure quick release mounting system that easily adjusts from 25. 4 to 34. 9 mm, easily fitting standard and oversized seat posts. The two pivot arm articulates for improved tire coverage and perfect bike fit. A stiff engineering grade polymer support frame is comolded to a softer more flexible material at the trailing edge for greater durability. A highly polished underside helps prevent dirt buildup and aids in