Continuous GMP duct rodders are constructed with a high‑strength fiberglass core offering industry-leading pulling and pushing strength. Rods come in 1/4", 3/8" and 1/2" diameters; available in standard core or detectable copper-core options; rods are marked every 2 ft. Leading end has tapered head and male threaded end fitting; trailing end has female threaded fitting. Designed to be used with GMP dispenser/carrier cassettes (steel tubular carriers, powder coated, with hand brake and large airless wheels on larger sizes). (Manufacturer data from gmptools.com; product-level page for MCN 89245 taken from distributor listing where the manufacturer P/N mapping differs.)