I purchased a Dogtra 2000NC single dog collar on February 3, 2005 and have used it less than 10 times. Unfortunately, I have realized that I need the Dogtra 2000NC two dog collar. With that said, I am selling my Dogtra 2000NC single dog collar for $310 shipped. I still have the receipt, the box it was delivered in, and everything that came with it. Let me know if you are interested.