SoloHitch - Line up the balls, attach your trailer
Buy Now: Yellow Balls to Align Trailer Hitch - Reese SoloHitch
The Solo Hitch from Reese Towpower is a convenient way for one person to align and level their trailer. 2 high visibility yellow balls sit atop telescoping rods. The rods have magnetic bases, so just set one on your ball mount and one on your trailer coupler. Once you adjust the heights, just back up your car until the balls meet - you're perfectly aligned every time!