Staun Automatic Tire Deflators (Heavy Duty 15-55 PSI) SAVE TIME with fully automatic tire deflation for a quick and carefree experience. HEAVY DUTY model adjustable from 15-55 PSI, factory preset to 35 PSI. EASY TO ADJUST to the desired pressure or simply use the factory preset PSI. FOUR DEFLATORS included with each set makes airing down all four tires at the same time quick and painless. PRECISION MADE in Australia.