Product review (5 stars): A fine replacement
After my humidifier stopped working abruptly, I called the original installers to inspect the unit.  At first they said it was a power issue and needed to install a new transformed.  I paid them about $200 for the job, and the unit worked initially, then stopped functioning again.  After another call out, they now said the humidistat was shot and needed to be replaced.  The part was under warranty, but they wanted about $200 to install the replacement part.  I asked the manufacturer to ship the part directly to me, but they refused, stating they would only issue replacement parts through their authorized network.  In short, I was out of luck.

Rather than pay $200 for five minutes worth of work, I ordered this replacement part to install myself.  Everything you need is included.  The prior humidistat came off with just four screws, and this one installed just as easy.  Unit started functioning again right away.  The humidstat seems more or less identical to the old model, I just hope it will function a little longer.

Overall, an excellent alternative that installs with very little effort.  Has been working fine for several months.