This is a pickup that was removed immediately after purchasing a used violin bass. I confirmed continuity between black and green wires with a tester. It's a Hofner type. The wiring has five wires: red, white, green, black, and a ground wire. I wonder if it's a humbucker type. Please research and use accordingly. The screws might tear the shipping bag, so I will loosen the screws and springs before shipping. It seems like it could be used on a self-made 4-string bass if the height is adjusted. #Hofner #ViolinBass #BassPickup