【High-Quality Materials】The rotating door hinge is made of high-quality 201 stainless steel, strong and durable. 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 the door more stable and flexible, and can be opened and closed tens of thousands of times. 【Easy to Install】The upper pivot comes with a retractable pin Compatible with quick and easy installation. The hidden rotating door hinge can be mounted on the upper level of the door and attached to a hole on the door's surface. 【Wide Range of Applications】The hidden rotating door hinges work great Compatible with swing doors, murphy doors, and much more. Excellent pivot kit alternative when door weight on traditional door frame hinges is an issue.