GM8900 Ground Check Monitor  Designed to monitor the integrity of the ground circuit of power distribution circuits in coal mines.

GM8950 Ground Check Monitor & Ground Fault Relay
Consists of a Ground Check Monitor and a GFR in a shared housing. Intended to be used on the same three-phase AC mine electrical circuit

GM8000 Ground Sentinel Systems:

For use without components at machine location


Providing pilot wire to ground short indication


For ground-continuity monitoring of AC mining cables