Featuring a unique chambered design, the Pressure Over Drive is ideal for seating even the most stubborn tubeless tires. The secondary chamber can be pumped up to pressure enabling a stainless steel footlever to release the compressed air in an immediate, continuous discharge, quickly and easily seating the tire bead\n The Pressure Over Drive features a durable steel and aluminum construction paired with a highly accurate and precise analog pressure gauge\n ABS1 Pro Tubeless Chuck, Presta/ M6x0.8 compatible\n Note: When using the Pressure Over Drive 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.