H-3640RDP.. Sold by the Each. Butler Tray Hinge holds leaf at 90 degree angle. Locks open in flat position. Round ends & solid brass, brushed finish. 3" long x 1 1/2" wide. Hinge is about 1/8 inches thick at the ends and the knuckle at the middle is approximately 1/4 inches thick. Overall length and width is more important than thickness. Thickness can be compensated by filling in or carving out space. Can be used on some drop front desk but not slant fronts. Buy 2, 4, 8, 48 and save. The more you buy the more you save. See enlarge for photo of front and back of hinge.