The 1399G10-BK is a black short spacer for the Anderson Powerpole® 15/30/45 series, intended to provide a keying feature to connector arrays. It is constructed from UL 94V-0 rated polycarbonate material with an 'as molded' finish. This spacer is used in combination with a long spacer on the mating connector half to create a polarized key, which prevents incorrect connections. This ensures proper orientation and secure mating in multi-pole connector assemblies.