It is a knuckle joint in showcase system. It can be used to connect two pcs of S1105B and one pc of S1128. When connected the two S1105Bs will form a 135° angle. It can be used where needs a 135°connection. This joint is used when putting together a table or cabinet. It weighs 0.250kg 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.