The OEMTOOLS Universal Cooling System Adapter Set is designed to fit most passenger vehicles and light duty trucks on the road today, eliminating the need for numerous adaptors previously required to test pressure in cooling systems. This adapter set works with a user-supplied coolant pressure tester kit, which can be purchased separately from OEMTOOLS (27069). The radiator pressure tester kit adapters feature a universal design that works with any cooling system pressure pump. The cooling system pressure tester kit adapters fit both radiators and plastic reservoirs. Our radiator test kit adapter set includes three adjustable diameter adapters to ensure proper sealing. This coolant pressure tester gauge adapter set also prevents damage that happens to plastic reservoir threads when the wrong adapter is attached with force. These pressure tester radiator adapters make it quick and easy to test cooling systems in most vehicles, saving you time and effort. FULL SPECIFICATIONS: (1) Expander, (1) 1 Inch Adapter, (1) 11/16 Inch Adapter, and (1) 1-3/8 Inch Adapter.