Du-Bro Wheel Collars are nickel plated brass. They feature enough stock so that threads will not strip and can be reworked for many other uses.
The 3/16" collars have a 3/16" (4.7 mm) hole and comes with grub set screw and a 1/16" allen wrench for tightening.
12 Per Pack
Dreamworks Model Products, LLC
775 Fentress Boulevard, Daytona Beach, FL 32114