J
Or South African or AmericanView attachment 164150
Guess you may need to be in the UK to fully appreciate this one.
Not a picture, but rather unusual instructions from an ebay listing for a pop tester:
S60H injector checker nozzle tester S60H
product description
Connect the nozzle holder to the appropriate conveyor
Discharge to the testicles. To test if the nozzle is clogged,
Press down on the nozzle tester handle -
Close and close the pressure gauge completely.
If the needle is free, the nozzle should vibrate
Grating whistle (exception: nozzle with holes
One or two small orifices that are no longer trembled by the quick joystick)