Yes sir. 3mm magnet. Fits right on top of the peg. No overlap. Peg is still small enough if you want to mount directly to the aircraft. Also worth mention. I have inserted 3mm steel blanks into my aircraft. Keeps them from bunching together in the piece tray, but give the magnets some strong to hang on to.
Can you point me in the direction of these steel blanks? I can’t seem to find any.