The Hamilton M-525 is the correct replacement valve assembly for the following humidifier models:
The Hamilton Valve Assembly for 200D, 400D & 800D is a replacement valve assembly for the Hamilton Model 200D, 400D, 800D, M-200, and M-240 Humidifiers. This Hamilton valve assembly includes a rubber stopper, which is not sold separately. The Hamilton M-525 valve assembly ensures the proper levels of fresh water within your humidifier pan and is a genuine Hamilton humidifier replacement part.
Hamilton Valve Assembly for 200D, 400D & 800D specifications: