The lance is what attaches to the end of the gun, and comes in many different lengths (depending on the application) and materials. There are aluminum, stainless steel and zinc lances available. The nozzle (or nozzles) is attached to the end of the lance. Lances have pressure and flow ratings so be sure to install the appropriate lance on your unit.
3-Nailer Combo Kit w/ Accessories
3-Nailer Combo Kit
1/4" x 50 Ft Noodle Air Hose with Coupler and Plug