The Newborn 125 Smooth Hex Rod Parallel Frame caulking gun has a steel skeleton frame that fits 1/4-gal. (28 oz.) cartridges and has a 10:1 thrust ratio for use with medium viscosity materials such as silicone. The smooth pressure rod design requires less user effort and is smoother operating than a ratchet-style pressure rod. The hook on the back allows it to hang on a ladder, and a seal puncture tool and a spout cutter are built into the side of the gun for opening cartridges without a knife.