Stop & Go 1085 Deluxe Tire Repair Kit The Gun is a spring loaded device that "drives" the plug into the hole The shaft of the plug expands under pressure to fill the puncture; The mushroom head of the plug seats on the inner wall allowing no air to escape; Maximum reliability from its" revolutionary design; Hard Sided Case measures 8.5" x 8.5" x 3" x 1" and weighs 2 lb. 3 oz