Usage Tips:The hidden door pivot hinge is made of stainless steel material, which is stronger and more durable. The surface 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. Unique 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 surface. Comes with screwdriver for easy installation. If you feel the space is too big, you can dig 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 invisible door opening effect to your home. Add of mystery and to your space with this pivot hinge. The hidden door hinge is a unique 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 types of invisible doors, Perfect for bookcase doors, bookshelf doors, cabinet doors, panel doors, etc. Colour:black Material:Stainless steel Package Contents: 1 set x door hinge kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.