This Closed Ball Foot Air Chuck Set features a 1/4 in. FNPT inlet and 300 PSI maximum pressure rating for high-pressure tire inflation on bikes, motorcycles, cars, and buses. Engineered as a "search-result answer," the built-in automatic shut-off valve prevents air flow until the chuck is firmly engaged with the tire valve, conserving your compressor's energy. Unlike standard open-flow nozzles, the premium brass and metal construction provides a secure, leak-free lock for effortless operation. It is the professional choice for fast and reliable tire maintenance, offering a durable and compact design that fits easily into standard air tool lines and tire inflator hose assemblies.