Product review (5 stars): Heat.  It's a good thing.
The mounting flange on this new unit was a little bit smaller than my 20-some year old heating element, but close enough that I could make it work.  (Better than too big!)  Disclaimer: I didn't actually have a part number from the old one, just had to guess and look at a lot of pictures and compare measurements. Arrived packed very well and brand spanking new, as advertised.