It sends pressurized air into the radiator using a pump and the appropriate connector. If there is a leak, the manometer will detect a drop in pressure. Capacity: 35 psi. The set includes: up to 200°C thermometer; pressure tester pump with 0-35 PSI manometer; test adapter for GM (Cadillac); test adapter for BENZ, GM (BUIK) and JEEP; test adapter for PEUGEOT, SUBARU, CHRYSLER, ACURA, GM (Nova, Spectrum, Sprint) MITSUBISHI, NISSAN, MAZDA, TOYOTA, INFINITI, GEO, SUZUKI, ISUZU and FORD; Adapter for HONDA, TOYOTA, SUZUKI, MITSUBISHI, CHRYSLER and ACURA; Adapter for BENZ (ML-class), GM (Achiva, Skylark, Grand Am 1992.2002); Adapter for VOLVO, SAAB, STERLING, CITROEN, RENAULT, FIAT, ALFA, JEEP; Adapter for VW (Vento, T4, Passat – 1996, Golf, Beetle, Sharan); Adapter for AUDI (A4, A5, A6), BMW345, VW (PASSAT – 1997 – 2002); Adapter for BMW; Adapter for AUDI AND VW; Adapter for FORD INTERNATIONAL, LAND ROVER, OPEL, JAGUAR; Adapter for BENZ (C-Class, E-Class, S-Class) and plastic case.