Stage 8 locking fastener solutions are fail-safe when used and installed as directed. They are removable and reusable and can be visually inspected, if the locking retainer and clip are present then no fastener rotation has occurred. The locking systems are used on the Space Shuttle, Caterpillar Tractors, Ford Racing, Armored Combat Vehicles and many, many other applications. 3/8 inch - 16 x 1 inch double hex head stainless steel fastener kit of 16 sets.