The ARES Tool 12-pc Master Cylinder Adapter Set includes 12 adapters all designed to work exclusively with ARES 70921, 18051, and 18053 Brake Bleeder tools. Round adapter sizes include 29mm, 34.5mm, 42mm, 43.5mm, 47mm, 49.5mm, 50.7mm, 56mm, and 74mm. The set works on disc and drum brake systems and is compatible with 90 percent of current master cylinder reservoirs. Additionally, the set includes a one-piece rectangular adapter for Chrysler and GM vehicles, a one-piece adapter for Toyota and Lexus vehicles, 10-pc round adapters, and a one-piece custom-molded storage and carrying case.