Overall Dimension (folded): 10mm / 0.39 x 22.5mm / 0.89 (Dia x Height); opening gap of two unfolded hinges: 5.8mm / 0.23, please refer the second photo to check detailed dimension. Flexible 180 degree opening angle allows you to open or close box at 0 - 180 degree you desired; hidden hinges with countersunk design makes them completely invisible from both sides and well concealed while using. Made of gold-plated and polished premium brass, these concealed hinges are sturdy and durable, shiny & beautiful and rust-resistant, have strong load-bearing ability and not easy to fall off. Package includes 4 PCS 10mm / 0.39 brass barrel hinges, roller rail design for smooth and silent opening, built-in screws help to fix or adjust tightness of placement, easy and convenient installation, just drill and insert the hinge to finish. Suitable for jewelry box hardware, folding table, cabinet door, handicrafts, wine box, small furniture or using on other wood, plastic, thick glass material; Not