Dripless SI300 Contractor Grade Heavy Duty Caulking Gun, 10 oz Cartridge Capacity, 16:1 Thrust Ratio Steel revolving frame caulking gun for 10 oz. cartridges Thrust ratio of 16:1 for use with high viscosity materials Has drip and non-drip settings; on non-drip setting rod retracts after each pull of the trigger to help prevent dripping Revolving frame allows cartridge to rotate for maintaining bead orientation when caulking around corners Hook on the back for hanging it on a ladder