Killark GRR-3 - Cast conduit hubs with integral bushings - Blank cover included - Replacement cover catalog number GRRBC - Compact size - Supplied with five hubs and three close-up plugs GR series are the go to outlet bodies for multiple hub configurations and are installed to protect conductors in threaded rigid conduit. Some configurations offer mounting lugs with cover included. All GR series are available in the copper-free aluminum with our superior electro-statically applied paint, some are available in our Duraloy® iron. Application: Conduit boxes installed in conduit systems within hazardous areas to: protect conductors in threaded rigid conduit, act as pull and splice boxes, interconnect lengths of conduit, change conduit direction, and provide access to conductors for maintenance and future system changes.