Vortex 526ZK-45 Black 45-Tooth 525-Pitch Rear Sprocket Utilizes the same Vortex design with a color anodizing that excludes sweeps, mud grooves and teeth. The result is a bright flash of color in red, blue, gold or black (available colors vary by bike model) with bright silver highlights. Lightweight CAT5 aluminum racing sprocket. 100% CNC manufactured in the U.S.A. Specially formulated alloy per Vortex specifications.