SINCLAIR INTERNATIONAL manufactures precision-machined stainless steel pilots for flash hole tools and Neck Thickness/Variance Gauges.
The pilots are designed to fit new, unfired case necks for rifle and pistol cartridges ranging from 22 to 45 caliber, excluding .50 BMG due to larger flash hole diameter.
This specific product is a 32 Caliber Stainless Steel Pilot Stop, suitable for .312-.313 caliber sizes.