Altech’s UL recognized insulated wire ferrules are made for use in the control circuit of a UL508A panel. Altech offers a wide variety of single and twin insulated ferrules for all stranded wire applications. No more loose strands, no more loosening terminations, and no more shorts caused by stray strands. These wire ferrules are made of tin-plated copper, and the insulating collar is made of polypropylene plastic.