BLTL-53 consists of Model TL-50, Model TL-51 and two large padlocks in one convenient package. Model BLTL-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 your padlock. Secures the adjustable top part of coupler. Fits all gooseneck style round or square tube designs.