This Harmony RSZ range is a plug-in socket. This plug-in relay socket is compatible with interface plug-in relay RSB range. This product is for RSB1A relays. It is compatible with RSB with 1 C/O contact, 12A, RSB1A120 relays. It has a rated voltage of 250V AC with an output rating of 12A. This premium product conforms to international standard and certifications.