This Amerec PC Board is a 6 relay 208V/240V for the 2 or 3 element old style AR, AK and 3K steam generator models: 4KW, 5KW, 6KW, 7KW, 8.5KW, 10KW, 12KW and 14KW. NOTE: It cannot be used on the AK or AX generators that came out in 2017, models: 4.5KW, 7.5KW, 11KW, and 14KW.