QBS-20 Self-Retracting Metal Utility Knife. The versatile QBS-20 Safety Utility Knife combines the durability of an industrial knife with the safety benefits of a self-retracting safety cutter. To prevent painful and costly injuries, the blade will spring-back into the cutter once the cut is completed. The unique integrated hinge design and easy-open dial make for a convenient tool free blade change. Plus, the all metal construction is extremely durable and features a comfortable ergonomic rubber grip. For better retention purchase with the UKH-326 Leather Holster. Fits SB-92, SPS-92 and HB-96 Blades. Holds 5 additional blades.