The Primo Plastic Drive Side Hub Guard is designed to protect the rear driver and chain from damage. The Nylon blend is light and has little to no drag on grinds, but will need to replaced more often than steel or alloy alternatives. Luckily the affordable price makes that easy. Universal design fits most 14mm rear hubs by sliding over factory hardware. Note: Only compatible with 9T and smaller drivers. Weight: 1.0 oz Note: Universal type hub guards will not work with most 14mm female axle hubs that use 3/8" axle bolts. However, if the hub uses 14mm female axle bolts, it should work fine.