Used in the following models: 400, 701, 501, 601, WH 55, WH 85, WH 110, WH 155, WH 199, WH 285, WH 399, AW 151, AW 200, AW 286, AW 400, AW 501, AW 601, AW 701, XP 400, XP 501, XP 601, XP 701, KB 400, KB 501, KB 601, KB 701, WB 51, Wall Mount WB & WH, WB 81, WB 106, WB 151, WB 211, FB 1500, Crest, FB 2000, FB 2500, FB 3000, FB 3500, KB 81, KB 211, KB 106, KB 286, KB 151, Lochinvar Parts, Pool Heater Parts, XLP, Hydronic Heater Parts, Lochinvar, Lochinvar, Lochinvar, Knight, Floor Standing KB