【High Quality Materials】The hinge of the revolving door is made of high-quality 201 stainless steel, which is strong and wear-resistant. It opens and closes very smoothly and can be used for a long time. 【Invisible Design】The door hinge is invisible, unlike ordinary door hinges that affect the appearance, it is installed above and below the door, and has a hidden and practical design. 【Flexible Rotation】There is a stainless steel ball inside the door hinge. The smooth steel ball makes opening and closing the door more stable and flexible, and can open and close tens of thousands of times. 【Easy to Install】The top pivot comes with retractable pin for quick and easy installation. The rotation hidden door pivot hinge can be mounted on the top level the door and is attached to a hole on the surface of the door. 【Widely Application】The concealed rotating door hinges work wonderfully for swinging doors, murphy doors and so much more. Excellent pivot set option when door weight stress on traditional door frame butt hinges is a concern., Manufacturer: afdg