RENTHAL SPROCK R 520 48T SI UL SC 123U-520-48GYSI

FRONT SPROCKETS, CNC machined from case hardened and core refined 655M13 Nickel Chromium steel, Machined self-cleaning mud grooves at each tooth to help increase wear resistance, Certain models available in ultralight design for a 10-15% weight savings, REAR SPROCKETS, CNC machined from a specially enhanced 7075 T-6 aluminum alloy, Machined self-cleaning mud grooves at each tooth to help increase wear resistance, All rear sprockets are the ultralight design making them 66% lighter than steel, yet incredibly durable