heavy duty hammer tacker, steel construction high carbon steel working parts, chrome finish, non slip grip handle, narrow crown, auto feed & drive staples lightweight, uses 1250 pack t-50 1/4" (tv# 137-190), 5/16" (tv# 137-364), 3/8" (tv# 137-406) and 1/2" (tv# 139-337) narrow crown staples.