Moose Offroad Dual Sprocket Dual Sprocket - 49 Tooth - Silver - YamahaFeatures Designed to outlast standard aluminum rear sprockets and is much lighter than steel rear sprockets Inner ring is made from 7075 T6 aluminum and the outer ring is made from heavy duty steel Self cleaning mud grooves between each tooth to prevent dirt build up Specs Product Name Sprocket Type Drive Style Dual Color Finish Silver Material Heavy Duty Steel Outer Ring 7075 T6 Aluminum Inner Ring Tooth Count 49 Chain Size 520 Mounting Position Rear