Universal Locking makes it perfect for our small crane systems such as the Cobra Crane I and the Cobra Crane Backpacker, as well as virtually any lightweight tripod systems. Adding wheels to your Cobra Crane is a snap with the addition of the Cobra Crane Lightweight Freewheeling Dolly System. Designed for smaller crane systems that need to be mobile and not confined to a track. This wheel set will give you an added dimension of professionalism and production values usually found in system selling for over five times as much. Made of a super light weight material it is light weight, yet extremely durable and rugged. It also folds down to make stowing and transport a breeze.