The hidden door pivot hinge is made of stainless steel material, which is stronger and more . The is specially treated to prevent rust and breakage, and the workmanship is fine to improve the service life. The hidden door hinge has a high load-bearing design, and the base supports up to 573LB/260kg. Say goodbye to unstable steel balls. pivot device allows flexible rotation. The top pivot features a telescoping pin that allows the shaft to be adjusted for quick and easy installation. Rotary hidden door pivot hinges can be installed on the top layer of the door and attached to a hole in the door . Comes with screwdriver for easy installation. If you feel the space is too big, you can out a groove. Up and down link function, 360 degree rotation. Using the multi-angle rotation of the rotating shaft and the powerful load-bearing function, you can add an door opening effect to your home. Add of mystery and to your space with this pivot hinge. The hidden door hinge is a upper and lower connection design structure, which is supported by the lower arm and the floor, thereby reducing the pressure on the frame. Suitable for various types of doors, Perfect for bookcase doors, bookshelf doors, cabinet doors, panel doors, etc., Weight: 2.36666238257 Pounds, Manufacturer: Aisuoka