This anti-vibration kit can be used to reduce vibrations in a cooled astronomy camera that can cause image degradation if the fan is unbalanced.  It's tested with ZWO cameras but may work with others.

This kit contains:

4 x Anti-Vibration Fan Mounts

4 x Silicone O-Rings

is a video covering how to install the kit.  The red silicone O-rings are installed between the round fan wire brackets for the screws holding the fan and the camera back plate.

Alternately, replacement ZWO fans can be found