These plugs enable high quality connection for hi-fi loudspeakers where large diameter cables are used. Cable or plugs up to 7mm can be inserted through the side of the plug and clamped by the screw mechanism or 4mm plugs can be stacked end on.
Each pair comprises one black and one red plug.
The wide body of these plugs makes them unsuitable for use with un-modified Quad 303 power amps and ESL 57 electrostatic loudspeakers. Suitable plugs for use with the 303 and ESL 57s, can be found here