A propane orifice. Ask your proane supplier if he also sells them. Otherwise you can buy them from whirlpool. Have you looked in the orifice area carefully, many come from the factory with a set attached to a small card.

If you convert, remember that gas pressures are very different between NG and LP and you will also have to change the spring in the regulator or perhaps there is a similar device like my Amana. I have a Amana range that is multi-fuel. You screw the orifice mount down for propane, up for NG. Remove the regulator cap and there is a small rod, one end says LP, the other NG. Very easy swap. Look under your regulator cap.

PS Don't forget the oven too!

Ma, I am assuming he is bringing in a unit that needs to run on his propane home so I skipped talking about the regulator. The home is likely already set up for LP so if I misunderstood the OP should tell us now.

Bob, I wasn't talking about the regulator on the house. Maybe there is no regulator on a dryer(?) but there is one on a range. That's where I had to readjust my regulator with the device I mentioned.

PPS.Forget the comment about the oven. Reread post and got confused with my stove comment.