Model TL-50 is precision-made of aircraft aluminum and will not rust. It features a 3/4 inch heavy duty steel Locking pin. Fits Hammerblow, Stallion, Superior and T.E.M. Gooseneck style couplers. To use, simply install the narrow end (looks like a goose's neck) over the coupler bracket near the handle. Bring the wide opening of the TL-50 into position over the wide part of the coupler. Insert the pin into the hole that offers the tighter connection, then install a padLock. PadLock not included, Part No. UTL864.