Evacuate and Refill in One System: Uses compressed air to create a vacuum, remove trapped air, and draw coolant into the cooling system. This two-step process supports cleaner, more efficient coolant replacement in automotive workshops and home garages. Vacuum Gauge for Leak Checking: The dual-scale gauge reads from 0 to -30 inHg, allowing you to monitor vacuum performance before adding coolant. If the system cannot maintain the vacuum level, inspect the radiator, reservoir, hoses, fittings, and related connections before refilling. Adapter-Stays-in-Place Design: Once the selected adapter is secured to the coolant reservoir or radiator opening, it can remain installed while switching from evacuation to coolant filling. This reduces repeated disconnection and helps simplify the service process. Six Adapters for Larger Cooling Systems: Includes five round adapters in 1.2, 1.4, 1.6, 1.7, and 1.8 in. sizes (31, 35, 40, 42, and 45 mm), plus one universal conical adapter. Designed for many cars, SUVs, vans, pickups, and medium or larger vehicles; verify the opening size before ordering. Complete Air Fitting and Sealing Set: Includes a vacuum generator with gauge, venturi assembly with American air fitting, one European fitting, two Japanese fittings, filling hose, eight O-rings, sealing tape, two hose clamps, and protective gloves for convenient cooling system service.