This clip locks your Frankford Arsenal X-10 at the top blocking it from dropping powder while you are setting up your press or just wanting to process brass. This eliminates the need to empty/remove the powder assembly for these tasks. 
 
Installation is simple, just raise the micrometer to the top, insert the clip and done! To remove, simply grab the pull tab and pull it back off. 
 
The clips fit tight and will not pop off during press operation and will not effect any other operation of the press.