red and black binding post connector with screw threaded terminal on a white background

active amplifier apparatus attach audio background binding black chrome circuit clamping closeup code color component connect connector contact current design detail device electric electrical electro electromechanical electromechanics electronic electrotechnics electrotechnology element engineering equipment fastener group inactive industry instrument insulated isolated lead loudspeaker measuring mechanical metal metallic negative nobody nut object pair part plastic positive post red repair replacement round screw service set silvered single store supply technical technology terminal terminate test thread two white wire