Gerni and Nilfisk-ALTO EGT2600 310 Bar pistol grip spray gun trigger G290114 threaded parts are 3/8" (Hose In) and M22 (Lance Out) Max flow 45 lit/min and max temp 150C No longer available.

Screw off the M22 fitting, and it's a 1/4" BSP screw fitting. That is the screw thread of the Gerni steel lances.

See the other spray gun pistol grips 

At the moment, standard postage is capped at a maximum of $25 within Australia, so maximise the saving on postage and buy something in the related parts below!