Square 490 Interested? Please Contact us All volumes can be bolted on or screwed on, are made of 13 layer ¾ inch (18 mm) high quality birch plywood, and coated with our special Blocz texture. - Symmetrical volume - Bomber T-nuts (metric T-nuts available upon request) Length 19.5 inches Height 9.5 inches T-nuts 28 Design options Base plate