This is the Mori 4.5 Slip Tip Pencil Point 5/16 - 8mm Thread Features: The medium slip-tips are the most popular slip-tips used for the 11/32" and 5/16" shafts. It&';s low profile and hydrodynamic design allows for the minimum amount of penetration resistance and maximum range. The tip is 11/32 in diameter and the adapter is 3/8" in diameter. Length is 4.5". The adapter thread is 5/16-24 NFT. "