Overall dimension (folded): 16mm / 0.63" x 33mm / 1.3" (diameter x height); Opening gap of two hinges unfolded: 8.1mm/0.32", please refer to the second picture to check the detailed dimensions. 180 degree flexible opening angle allows you to open or close the box at 0-180 degrees as you like; Concealed hinges with countersunk head design make them completely invisible on both sides and well hidden when using. Made of premium brass with gold plated and polished finish, these concealed hinges are sturdy and durable, shiny and beautiful, rust resistant, have strong load capacity and do not fall off easily. Package includes 4 pieces 16mm/0.63" brass barrel hinges, roller track design for smooth and quiet opening, built-in screws help to fix or adjust the tightness of placement, easy and convenient installation, just need to drill and insert the hinge to complete. Suitable for jewelry box hardware, folding table, cabinet door, crafts, wine box, small furniture or use on other wood,