Killark BL-90-1 - Threaded for rigid conduit or IMC - Smooth integral bushings to prevent damage to wires Killark elbow series designed to change direction in rigid IMC conduit systems. Our non-capped elbows offer a 45° to 90° change in direction where space is limited for pulling conductors. This is series is offered in our copper-free aluminum and tri-coated Duraloy® iron, both painted with our superior corrosive resistant electro-statically applied powder coat paint. Application: To change direction in rigid or IMC conduit systems.