Allows bleeding master cylinders on or off vehicle. Kit contains plastic adapters in standard or metric sizes, standard: two-3/8�-24, one 7/16�-24, one- 9/16�-18, one-9/16�-20 and two-1/2�-20, metric: four-M10 x 1.0, two-M10 x 1.25, one-M11 x 1.5, two-M12 x 1.0, one M12 x 1.5 and one-M13 x 1.5, hose holder, 20� hose, thread gauge and instructions.