Things Every Homeowner Knows About Hiring HVAC Companies: Water Panel for Trane THUMD500APA00B

I need to buy a replacement water panel for a Trane THUMD500APA00B humidifier. I bought some off of Amazon several years ago. I foolishly used the last one without saving the box or taking a picture of it. I have seen some sites that claim that other brands have equivalent replacements. I am not too sure about these. Can someone point me in the right direction?

Thanks in advance.