These parts allow you to mount standard 12mm hex wheels to your 3D Sets Rancher.
The parts include a 12mm sleeve and a 12mm diameter washer to keep the 3mm screw centered.
Don't know what this is? Check out the fully 3D printable 4WD RC car over on https://www.3dsets.com/ . Buy it, print it, bash it, break it, print replacements and drive it again!
The author hasn't provided the model origin yet.