Genuine BOSCH AQT 35-12, AQT 37-13, AQT 40-13 Pressure Washer Trigger Gun Handle. Color: Black. Pressure Washer Trigger Gun Handle. Customer need to remove the hose pipe O-ring and wrap thread seal tape on O-ring base(channel) then wear the O-ring on base. Genuine BOSCH AQT 35-12, AQT 37-13, AQT 40-13 Pressure Washer Trigger Gun Handle