GN1 - Gooseneck Coupler and Stem by Popup Towing Products. The replacement 2-5/16" Gooseneck Premium coupler and stem self-latches and releases remotely with a cable that can be conveniently located near your trailer jack handle. The gooseneck trailer stem is 4" round high tensile steel tubing. It has a moulded hitching guide for easy coupling. The gooseneck coupler is precision cast of Chrome Vanadium Steel; Stainless steel latching pin; Stainless steel spring; powder coated Black. The coupler & stem comes with all necessary hardware and coupler release cabling. Easy and simple to install, remove your old stem and simply replace it. 24,000 lb GWR.