This Wilwood O-ring is specified at .301-inch inner diameter (2-011) for 211B/C applications and is intended as a replacement caliper seal for compatible Wilwood rebuilds. The O-ring restores required sealing where the smaller .301" ID dimension is used, helping preserve hydraulic pressure and piston movement. Use it as part of seal replacement during caliper servicing.
Wilwood .301ID 2-011 O-Ring 211B/C