These Heavy-Duty Staples Are Designed For Safe and Secure Insulation Of NM (Romex®) Cable Gauges 14/2, 14/2G, 12/2, 12/2G, 10/2, and 10/2G, and Other Wire Up to 31/64-Inch (12 MM) In Width. For Exclusive Use With Klein'S Loose Cable Staplers (Cat. Nos. 450-01 and 450-100). These Ul Listed Insulated Staples Are Available In Packs Of 300.