Selby's Shelf Magic Hidden Wire Shelf Supports are a stylish, affordable way to install shelf supports. They're one of our most popular shelf supports, too! These Magic Shelf supports are completely hidden after installation. Available in 5 sizes, measured center-to-center. MINI size can be used individually for any hole spacing. Installation: Drill a series of 1/8" diameter x 1/2" deep holes in the side wall, horizontally separated according to the wire selected and the shelf depth.