These black aluminium extrusions are used to connect together Multipanel's Classic, Heritage and Linda Barker waterproof wall panels at external corners. The channels are silicon sealed, allowing the panel to slot in for a neat, unobtrusive finish. They are durable, waterproof, and available in four different finishes, measuring 2450mm long. This specific profile is a Type B External Corner Aluminium Extrusion in Matt Black, 2450mm Long, MPN 21261.