Wilwood’s Tandem Aluminum Master Cylinder is available in 2 bore sizes 1 Inch and 1-1/8 Inch; and 3 finishes, plain, ball burnished and black e-coat. 7/8 Inch bore master cylinders are designed primarily for manual applications and features a pushrod. The 1 Inch bore can be used in manual and power assisted applications and does not come with a pushrod. The 1-1/8 Inch bore is designed for use primarily with power brake applications, either from vacuum assist or hydraulic assist systems. They’re designed for mount flanges from 3.22 Inch to 3.40 Inch, common measurements for most domestic cars and trucks from the mid 1960s to present, and offer fluid outlet ports on both sides of the bore. The stroke is set at 1.10 Inch with a volume ratio of 2:1 between the primary and secondary chambers. Machined from high-pressure die castings, each master cylinder weighs only 3 Pound, a 75 Percent weight savings over most cast iron OE type master cylinders. We also offer a our combination proportioning valve kit, which features brackets and stainless lines specifically for use with these master cylinders.