It is a knuckle joint in showcase system. The bottom extrusion of the knuckle joint ca be connected with V2000. And the other two extrusions can connected with beam extrusions, V2100, vertically. This joint is used when putting together a table or cabinet. It weighs 0.135kg per each. Screws are used when the knuckle joint is to be fixed to the extrusions. It is simple to assemble, easy to disassemble and it is robust and durable. 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.