This kit allows the thumbscrews of the 410, 610, and 1250 lenses to be replaced with set screws. These set screws allow the overall diameter of the lens to be decreased while allowing increased vibration resistance for the lens.
The kit includes 2x M2x5 set screws, 2x M2x7 set screws, 1x M2x5 button head screw and Allen keys.