This knob can only be used on the left front or right front of the heater,knob has ribbed. Baseboard heater knob has ribbed sides for ease of grip when turning. Compatible model numbers: Use with engineered products 1800,1900, 2500, 2600, C1800, and C2500 Series Model C baseboard heaters and TA1AW,TA2AW,TA1ANW,TA2ANW,TA1AWC,TA2AWC,TA1AWCA,TA2AWCA,TA1ANWCA,TA2ANWCA, FTA1A,FTA2A.
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