HKOMPAC/8S… Drop Front Desk Drop Flap Hinge is 5/16″ thick) for 5/8″ wood in Black. Fits a 30mm (1-3/16 inch diameter) hole. Sold by each not pairs. Drop Flap Hinges (90 degree opening) Flap opens flush with inside shelf. Fits flush in door and shelf surfaces. Completely concealed from exterior. Uses 30mm Forstner or flat boring bit 5mm from edge of panel. White or Brown Nylon with steel & brass linkage.