Designed or frequent use providing professional fastening results in a variety of concrete, masonry or steel applications The RS22 is a traditional trigger operated tool Positive barrel and load retention prevents barrel from opening freely, allowing easy horizontal and overhead fastening Powder load automatically ejects after each use Ergonomic design for operator comfort Heavy duty all steel construction 90 day warranty Uses standard .22 caliber single shot powder loads 2(Brown), 3(Green), 4(Yellow) 3/4in O.D. muzzle bushing 3in maximum pin length