Staun Tyre Deflators are the easy way to deflate your tires for increased off-road traction. They simply screw onto the tire valves to automatically deflate all tires to your preset pressure. Factory Preset to 18PSI. Stop wasting 30 minutes fumbling with your keys or an old screwdriver and a pressure gauge. "Staunies" will have you on the trail in just a few minutes, quick and easy.