The OEMTOOLS Radiator Adapter for VW models works with any standard coolant or radiator tester kit to check for coolant leaks, making these radiator pressure tester adapters a must-have tool for any VW coolant pressure tester kit or radiator tester adapter kit. Fixing damages that are caused by coolant leaking from a Volkswagen radiator can be expensive and time-consuming, causing you frustration while costing you hundreds of dollars. But our radiator cap adapter allow you to say goodbye to towed vehicles and spending additional money on new transportation. These adapter tools help prevent engine damage before it occurs by working with your radiator test kit to identify leaks, saving you money and time. This coolant leak detector adapter is simple to use. Just place the radiator test kit pressure adapter into the radiator, tighten it, attach the pump, and pump the pressure pump until it reaches the specified PSI. COOLANT PRESSURE ADAPTER SPECIFICATIONS: (1) OEM Adapter for Volkswagen Models with Female Threaded Filler Necks (1990-1998); Diameter: 57 mm; Thread Size: 3 mm; Dimensions: 4.20 Inches x 4.60 Inches x 3.30 Inches; Weight: 1.05 Lbs.