Tacmate Stapler, Ergonomic, Heavy Duty, Compact, Polymer Housing Construction Is Durable Yet Lightweight, Shorter Grip Span Makes It Comfortable For Hours Of Continued Use, Non-Marring Tip Is Designed To Help Protect The Work Surface From Scratches Or Dents, Easy To Store & Less Likely To Cause Any Damage If Dropped, Uses T50 Staples: 1/4" TV # 137-190, 5/16" TV #137-364, 3/8" TV #137-406 & 1/2" TV # 139-337.