The Amphenol SP-4-MC is a 4-pole loudspeaker chassis connector with a round (circular) flange, the Amphenol equivalent of the Neutrik NL4MPR speaker socket. It is fitted to passive loudspeaker cabinets, power amplifier back panels, stage wedges and speaker patch panels to accept a 4-pole locking speaker cable connector. Four poles let one cable carry two channels, for example bi-amplified cabinets or two passive speakers from one run. The round black thermoplastic flange has through holes for screw mounting and 3/16 inch solder tabs for wiring. Amphenol rates it at 20 A per contact, IP20 (IP40 when mated), UL94 HB, -25 to +75 °C and 5,000 mating cycles. It accepts Amphenol SP series cable connectors such as the SP-4-F and is used by installers, speaker builders and hire companies. Supplied as a single connector.