The Custom Grip Handle features a textured, non-slip grip handle for better airbrush control. The new ergonomic design adds comfort while holding your trigger airbrush. The Custom Grip Handle fits the following Iwata airbrushes: â?¢ Kustom TH â?¢ Kustom TR â?¢ Revolution TR1 â?¢ Revolution TR2 Â Assembly Instructions for the Custom Grip Handle: 1. Thread (A) onto airbrush. 2. Slip the Handle (B) onto the Air Valve Extension (A) so that the threads of (A) come through the bottom hole of (B). 3. Screw the Handle Nut (C) snugly onto (A).