Transformer Differential Protection DMS7002
Used for differential overcurrent protection of two-winding transformers.  It has an adjustable bias to prevent spurious trips during through-faults.  Unlike the equivalent static relay (DTT7031), the DMS7002 does not require interposing relays to correct for amplitude and phase angle shifts between the primary and secondary side of a transformer. 

The DMS7002 incorporates a "watchdog" contact linked to a self-diagnostic system to alert users in the event of loss of auxiliary supply or microprocessor failure.  
ANSI function: 87 T

See the PROCOM series homepage for the full brochure of DMS7000 products