Enjoy the convenience of a hitch step, plus the added safety of a sonar back-up system with the Dolphin Sonar Step. This sturdy step gives you easier access to your truck bed or roof rack, plus a sonar system that detects hard-to-see objects behind your truck or SUV when you’re backing up. The sonar plugs into your existing trailer adapter and sends signals to a wireless receiver that fits your 12-volt socket. The transmitter emits three different beeps that let you know how close you are to whatever’s behind you. Installs easily and comes with a locking hitch pin and anti-rattle pad. Fits 1¼" or 2" hitch, attaches to 7-way or universal adapters. For use with hitches over 15" from road surface.