4 each plastic wheel collars with set screws and wrench for 1/16 and 1/5 mm axles. Lighten up with Du-Bro Micro Wheel Collars. Designed for electric flyers with .047" (11.938 mm) to .062" (15.748 mm) axles and use set screws for a secure fit. These Micro Wheel Collars are 50% LIGHTER than standard 1/16" brass wheel collars. Each collar weighs 0.42 grams. Each pack includes (4) collars with set screws and a .050" allen wrench. Made in USA