This is a UL reconized/CSA Certified Solid state relay. It is compatible with the MTI OTF-1200X series furnaces with Resistance Wire Heating Elements. SPECIFICATIONS Current: Up to 25A, Voltage: 24-330V max, 4-32 VDC activated Complience: UL recognized, CSA, CE EN 60947-4-3 Repalcement part for GSL-1700X-60-III-F3LV MSK-115A