The R-N-R Rolling Thunder Edge Protector utilizes rollers turning on sealed ball bearings for incredibly smooth rope pulls and the least amount of friction possible. This low profile unit allows litters to be easily raised over the unit and will provide a smooth pull over various types of edges. The unit can be wrapped around objects and have the ends secured with carabiners. The unit folds up into a 7? cube for easy storage and deployment. The side plates are manufactured from a high strength aluminum alloy. Weight 2.6 lbs. Made in U.S.A..