PROFILE RACING ELITE SPLINE DRIVE C/W-19MM-3/32" RACE SPLINE SPOCKET-19MM: CNC machined 7075 aluminum from the US, no sprocket bolt needed thanks to a CrMo steel insert for direct power transfer. Compatible with 19mm splined axles, 3/32″ tooth width for most BMX chains. Sizes: 36t - 45t; Colors: silver, black, red, blue, gold; Weight: 36t: 4.9oz, 40t: 5.25oz, 45t: 6.05oz. **NOT COMPATIBLE WITH PROFILE RACING ELITE CRANKSET** Spline drive sprockets unsuitable for Right Side Drive 2-piece cranks (insufficient space). Compatible with Left Side Drive 2-piece cranks, however.