1- piloted 3/8 -10 with a .308 flat minor diameter that fits the pins they sell.
2- piloted 3/8-10 with a .312 flat minor diameter that fits pins that some cuemakers have custom-made. (I was told Chudy and Sugartree).
3- regular 3/8-10 tap without a pilot.
The pilot on the first 2 is a superior design. It is sized the same as the bored hole to ensure that the tap fillows the hole perfectly.
Hope this helps.