Made of two plastic laminate (plastic laminate design will vary from one to the other) covered particle boards with 5 stainless steel ball bearing, screwed into the inside surfaces of the boards. The 8″ turntables have a 4″ bearing capable of supporting at least 200# and the 12″and 16″ have a 6″ bearing capable of supporting at least 300#. To clean, wipe with a damp sponge (do not submerge the turntable in water). Has a 1 year warranty.