DC Three-Position Polarized Relay is manufactured by Hytronics Enterprises. Hytronics Enterprises is an ISO 9001:2000 awarded company. Hytronics Enterprises also manufactures various types of vital safety relays of both types i.e. with metal to carbon technology & with metal to metal contacts.

DC Three-Position Polarized Relay is available with centre biased armature for use in railway signaling circuits and for use with single line and double line block instruments in Electrified and non- electrified sections. The contacts are silver to silver. The relay conforms to IRS: S 31/80.