The Dripless SI300 Contractor Grade Heavy-Duty caulking gun has a steel revolving frame that fits 10 Oz cartridges and has a 16:1 thrust ratio for use with high viscosity materials such as silicone, latex, drywall, sub-floor adhesives and polyurethanes. The gun has both drip and non-drip settings. On the non-drip setting the rod retracts after each pull of the trigger removing pressure from the tube to help prevent dripping. 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.