Utility Knife : 1.ABS case & rubber jacket , 2.cutter knife with 3 blades & SK4 material 3.Self loading 4. with srew lock Utility Knife :1.ABS case & rubber jacket ,2.cutter knife with 3 blades & SK4 material, with three cutting edge .50% sharper than others 3.Self loading 4. with srew lock utility knife