Wilwood’s Compact Tandem Master Cylinder. The 1” bore can be used in manual and power assisted applications but does not come with a pushrod. They’re designed for mount flanges from 3.22” to 3.40”, 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” with a volume ratio of 2:1 between the primary and secondary chambers. Machined from high-pressure die castings, each master cylinder weighs only 3lbs, a 75% weight savings over most cast iron OE type master cylinders.