They are the same. I suspect the difference between the "3" and "4" is just a production run number. I wish I had bought a bunch of them at 18.00 though. I think somebody made a mistake at my Harman dealer on that one.
It could be a production run number, but evidently it makes them 2x the price...!
Let's hope they last twice as long. I suspect my old grates were originals. Not sure how old this stove is, I bought it used.
If you are wishing you had bought "a bunch of them", does that mean you have replaced them before??
What is the "normal" lifespan of grate inserts? I am a relative novice at burning coal, this being my third winter living with (and loving) my coal stove.