These heat sinks will help to keep your stepper motors cool.
Designed to be used with a 40mm CPU fan, the heatsink will help to prevent the heat from the stepper motor from being transferred to your printer chassis. This can be disastrous if your chassis is made from PLA.
The heatsink should allow you to run the stepper motor at its full rated current without fear of melting your PLA components.
They are made from highly conductive aluminium and anodised black to help with radiative heat transfer and because it looks good.
This kit comes complete with a 40mm fan and 4x mounting screws for the fan.