Plugging device drives the plug into the hole with a twist of the Allen wrench, plug then expands under pressure to fill the punctured area, a firm pull on the stem seats the mushroom head on the inner wall allowing no air to escape. Revolutionary device easily installs mushroom-shaped rubber plugs into all tubeless tires on the wheel. Kit includes:. Plugging device. Nozzle adapter. Rasp tool. Probe tool. Retractable razor blade. Allen wrench. 15 - mushroom plugs (5/16" diameter x 3/4" long stem). Laminated instructions. 4 - 16 g canisters of CO² gas. 4" flexible adapter with solid brass fittings for the most effective repair possible without dismounting your tubeless tire. 5" x 7-1/2" x 1" zippered pouch. CO² cartridges cannot be transported on an aircraft..