Yea, they come stock with an 8mm. I always run a 7mm in them because it makes it a little easier to tune and if its tuned right you can push 12 to 13 mins with this thing. Any 8mm I tried I could never trust going a 10 min heat without pitting. If you have any of your old 7mm B5 inserts bring them they work perfect in the Argus.