Master Mechanic, 20 Gauge, Pneumatic Fine Wire Stapler, Aluminum Magazine Holds Up To 100 Fasteners At A Time, Comfortable Grip, Anti-Dust Cap, Non-Marring Tip Helps Protect Your Work Surface From Any Scratches Or Marring Inflicted By The Tool, Ideal For Upholstery, Screen, Crafts, Insulation & Roofing Felt, Compatible With Arrow T50 Staples & Generic Fine Wire Staples, Accepts 20 Gauge Staples Ranging From 1/4" To 9/16".