Featuring a unique chambered design, the Pressure Overdrive is ideal for seating even the most stubborn tubeless tires. The secondary chamber can be pumped up to pressure enabling a stainless steel foot-lever to release the compressed air in an immediate, continuous discharge, quickly and easily seating the tire bead. The Pressure Overdrive features a durable steel and aluminum construction paired with a highly accurate and precise analog pressure gauge. An extra long, nylon-reinforced braided hose terminates in our Presta and Schrader compatible ABS-1 Pro chuck offers plenty of versatility. Note: When using the Pressure Overdrive as a regular pump, you must fill the air chamber before air will begin to flow into empty tire/tube. When topping off a tire/tube that already has pressure in it, the chamber will have to reach the same pressure the tire/tube is at first before it will begin to inflate it further.