One of those quirky gadgets that can be really helpful. Mount the roller assembly on any flat surface such as a sawhorse or work table and the steel ball bearings will enable you to move whatever you are working on in any direction. Use it with a table or band saw, sander, drill press and other power tools. Made by Crawford, model WM31m, 18". In original box, has not been used. Includes: . twelve 3/4'' steel ball bearing rollers . 18" long steel housing . mounting hardware . instructions