For stapling all types of wiring from 1/4" (6mm) to 5/16" (8mm) in diameter. Ideal for installing wiring for telephones, antennas, intercoms, and alarm systems. Can be used on plastic cable, hollow tubing, radiant heat cable, and virtually any application of wire. This cable gun includes 2 sizes of insulated staples, 5/16" (Model No. 326418) and 7/16" (Model No. 326427).