LC360 STANDARD Precision 0.4 in ( 9 mm ) blade cutter knife with comfort grip Equipped with an Endura-Blade Slide blade lock system Non-slip Elastomer grip / 561 HEAVY DUTY Heavy-Duty 0.7 in ( 18 mm ) blade cutter knives with comfort grip Equipped with an Endura-Blade Automatic Blade Lock system | LC561 Dial Lock Blade Non-slip Elastomer grip LC660 EXTRA HEAVY DUTY Extra heavy-duty 1 in ( 25 mm ) blade cutter knives with comfort grip Equipped with a Rock Hard Blade Auto blade lock system *** Replacement blades come in packs of 10 or 50 for both standard and heavy-duty knives