Flexible conduit aluminium core. This non-jacketed flexible aluminum conduit has many universal wiring applications. It is often referred to as ''Greenfield'' or ''Reduced Wall Flex''. Type ABR is formed using a high strength aluminum alloy strip. The result is a conduit with similar characteristics to those of type BR steel but at about 1/3 the weight. General use: In accordance with CEC Rule 12-1002 (1) the flexible metal conduit is permitted in or on buildings of either combustible or non-combustible constructions.