Thermopile 24" for Majestic Gas Fireplace 750MV - 14-1021 FC FREE Tech Support. Use amazon messager to contact Seller 3/8" Diameter; 24" Wire w/ Spade Connectors 3-5 Year Lifespan 750 Millivolts. Thermopile 24" for Majestic Gas Fireplace 1 Year Warranty; 30 day return policy (unused items only)