#10-32 by 5/16 set screw. This set screw is used for the following applications on the gatling gun kit:
-Rear Sight (1)
-Crank handle (1)
-Flash hider/muzzle brake (also positions the barrel shroud, 4 per)
This product can expose you to chemicals including lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov. 
