Universal Gun & Quicklock™ Style guns have a simple locking mechanism that holds the sheaths to the gun. These guns function with either slit OR un-slit bovine sheaths equally well. They also accommodate both 1/4cc and 1/2cc straws. The unique locking ensures that the sheaths push on tightly to the end every time, eliminating the potential for 'bend-over' at the tip from a poor fit. The plunger is also secured to the gun, it will slide, but cannot slide all the way out. This allows you to invert the gun to load straws without losing the plunger. Can be autoclaved to 120°C.