The 30 oz. Air Assist Bulk Loading Gun is a single-action air-powered bulk caulk gun with 18" steel barrel. Generates 120 psi of pressure. Manual pull allows better loading sensitivity. (The air assist is only for application, not for loading caulk/chinking.) Comes with 3 orange cone nozzles and steel 1/2" ID nozzle. Now Includes Nozzle Adapter for fitting most T017-32 style nozzles. If you cannot regulate your air pressure at the source we suggest adding a small dial regulator such as our #445-1 just below the handle. Made in the USA.