Fast and easy-to-use for fastening to concrete, masonry, and steel. Great for wall applications and between studs. Positive barrel and load retention prevents barrel from opening freely allowing easy horizontal and overhead fastening. Uses .22 caliber single shot powder. Powder load automatically ejects after each use. Easy-to-use trigger action. Padded handle for recoil reduction and ergonomically designed for added comfort. 2-1/2" pin capacity (3" with washer).