Shrinkfast 975 Heat Gun Orifice Holder - Part# 1
The Shrinkfast 975 Heat Gun Orifice Holder (Part# 1 on the diagram) screws directly into the back of the gun at the hole in the Inlet (part #8). The Orifice Holder holds two O-Rings (parts #2 and #4) and a Filter (part #3) on the outside of it. It also allows the Orifice (part #5A) the screw directly into it.