Attributes . O-Z/Gedney nonmetallic insulating bushings are used to protect wires and cables at entry and exit of threaded rigid conduit and IMC; O-Z/Gedney also has a plug to be used with metallic or nonmetallic bushings to prevent the entry of dirt or dust; Type ABB is a combination of type A and BB bushings for insulating cables passing through metal boxes or troughs; High impact black thermosetting phenolic bushings, with at 150 DEG C UL temperature rating, that will not soften, melt or burn . Names