Davis Prop Sox 
Prop Sox protect your expensive propellers from road kickback when towing and promote safety by increasing your propellers' visibility.
Prop Sox are made of bright plastic and simply slip over each propeller blade. The sox are held in place with a rubber cinch strap. Set of three socks, cinch straps and 3 reflector hot-dots included. For use when your boat is out of the water only.
Quick Guide (pdf)