Shocker Hitch 30,000 lbs Gooseneck Coupler for 2-5/16" Ball -4" Round Tube . The Shift Lock™ gooseneck coupler by Shocker Hitch is now available with a direct replacement inner tube stem with Shift Lock coupler. Upgrade your gooseneck trailer with the easy to use, patent pending dual latching Shift Lock coupler for gooseneck trailers. It is rated at 30,000 lbs. and is the only gooseneck coupler that captures ball on both sides. Plus, at a glance, you can see if the gooseneck coupler is locked on the ball. The Shift Lock handle makes it super easy to hook up and disconnect the gooseneck coupler from the ball .Our Shift Lock Coupler is easy, fast, and safe. We use dual latching simple sliding rods made with alloy steel to lock the ball in place. Works great on gooseneck style trailers; dumps, flatbed, horse, race trailers and more. Completely replaces your factory stem & coupler with a replacement stem & Shift Lock coupler. -Installs in minutes -Manufactured with American Steel-Fits 4" ID Standard Trailer Coupler Tubes Built with angled pin -Works on PJ or Diamond C Trailers-Fits 2-5/16" hitch balls -Note: Does not include the outer sleeve