If you are using a T profile you will need one of these. I ordered both sizes plus mandrels for each. They cleanly cut through about 80 linear feet of MDF. They are high quality and you can't beat the price.
I used this cutter to cut a groove for a 3/4 inch T-moulding on an arcade machine. It was the perfect width for a nice t bar fit that wasn't too tight so it could be removed in the future if needed.