We installed one last year, bought it at an RV show for $89 incl tax. Easy install, works really well, just like a motion sensor light at your home driveway or sidewalk, it will turn the light on as you approach the rv at night. Save you from stumbling in the dark without leaving lights on all the time. It also has a battery charge indicator built in. You can also flip the switch twice and it will stay on. Would recommend.
Daniel & Donna Leonard
2011 Ram 4500 SLT 4x4