This is a replacement collet for Wera Kraftform Micro Screwdrivers.

Wera uses color to denote the type of head (philips/hex/flat/torx etc.), but if you are solely working with one certain type like I do and would like to use the collet as color code for Sizing instead, here is the model for you to print in different colors. Alternatively if you lost your original they can also servo as replacements.