Deltron 550/551 series. Superior quality 4mm single pole plugs and panel mounting sockets. Contact material nickel-plated brass. Plugs have solder bucket connection, and stainless steel contact spring, barrel manufactured from durable moulded acetal. Sockets manufactured in acetal, with solder bucket connection. Panel cutout 8.1mm Plugs and sockets rated 10A. RoHS compliant