Item 6 - M-Model Diagram. The 90° nipple carries pressurizing air into the lid of the 1 qt. cup. Two things to know: a blocked nipple is on Fuji’s list of causes for a gun that sprays in pulses, and when you refit the cup diaphragm its small air hole must not sit directly below the air hole in this nipple. Genuine Fuji Spray part for optima