Thermostat Regulator for GRID's and SG Grils Diagram #17 for GRID's GRID-16 uses 1 thermostat GRID-24 uses 2 thermostats GRID-30 uses 3 thermostats Diagram #2 for SG's SG-811, SG-811/F, SG-811E, SG-811E/F uses 1 thermostat SG-813 uses 2 thermostats