The ESCO Pro Series Tire Bead Seater Tank (Model 20391) is designed for commercial and personal use on all tires ranging from ATV to 24.5 in. truck tires. Redesigned butterfly quick release valve for faster and easier air release. Works great on lawn, garden, ATV, automotive, truck, tractor and RV trailers. Ordinary air supply lines for inflating tires do not deliver air quickly enough to expand a large or inflexible tire sufficiently to seal the tire bead onto the wheel or rim. The ESCO Pro Series Air Tire Bead Seater Tank is a portable tank of compressed air which is delivered by a quick-acting air release valve through a larger diameter barrel into the tire. Because a larger volume of air is delivered very quickly, the tire bead is easily lifted onto the rim, creating an air tight seal to allow the tire to be inflated. Built in pressure gauge to refill the tank from any standard air compressor up to 200 psi.