Check-Synch Relays: NPSC800-1 and -2
The NPSC800 relays replace the STS7041 (static) relay for checking synchronism between two sources or across a bus-tie.  There are two variants:

NPSC800-1 (available in the "R-case" modular design as NPSC800R) checks synchronisation only.

NPSC800-2 (available in the "R-case" design as NPSC800RE) allows operation of live/dead line and bus. It can also manage the reconnection of two sections supplied by the same source. 

ANSI function code: 25 

These relays are part of the NP800 range, offering multi-function protection and communication via Modbus (RS485) or Modbus TCP (Ethernet).  A full brochure is available on the NP800 range page