Hi Dean.

They were small size open end at one end and had a pellet probe on the other end..They were made to fit the adjuster screw on the front of LJ's early BSA's Improved Mod B..Improved Mod D's and even the Later Last BSA Pre-War Rifles ie;- A Light Pattern CS's C's and the like with one hole trigger block's..Size across the Flat..0.25"..There must be thousands about in draws and tool boxes ..The big trick is finding them..


Regard's

Inproved..Steve..