Create your own display units, spice racks, serving trays, storage shelves, TV/computer stands and much more. Pre-assembled, zinc coated metal units give durable service and glide smoothly on a ring of enclosed steel ball bearings. Easy to install using the pre-drilled holes in the ring as a guide. Make 5/32 holes in your project and attach the ring with self-tapping #6 screws of suitable length. Oil the bearings, if desired, for easier rotation. These 3 square rings are a slim 5/16 deep but they hold a surprising amount of weight; up to 200 lbs. This offer is for 10 brand new 3 bearing rings.