Wilwood High Volume Tandem Master Cylinder - 1 1/8in BoreWilwoods Tandem Aluminum Master Cylinder is available in 2 bore sizes 1. 00 and 1 1 8; and 3 finishes, plain, ball burnished and black e coat. 7 8 bore master cylinders are designed primarily for manual applications and include a pushrod. The 1 bore can be used in manual and power assisted applications and does not come with a pushrod. The 1 1 8 bore is designed for use primarily with power brake applications, either from vacuum assist or hydraulic