I have just received my new Dogtra Arc collar in the mail. I love it already. The smaller receiver is nice for small dogs and doing yard work. I have it is a little hotter than my 3500. The only thing that will take some getting use to is the nick and continuous button is the same and yoh have to flip a switch. Unlike the 3500 there are two seperate buttons. But other than that im very happy with it. Call your local rep and order yours today!!