It is a knuckle joint in showcase system. It can be used to connect two pcs of K805 vertically. The feet which connect with K805 of the joint is 30m. The third feet of the joint is 40mm. This joint is used when putting together light showcase or cabinet. It weighs 0.119kg per each. It works with some light extrusions. Screws are used when the knuckle joint is to be fixed to the extrusions. It is simple to assemble, easy to disassemble but best do not assemble and disassemble frequently. It is made of zinc. The products of LingTong are green and environmentally friendly. If there are some relative needs, LingTong will provide the best service for you in exhibition construction.