The Tracker Classic Dog Tracker is available in two frequencies, 216 MHz and 217 MHz with the Strike Collar for Coon Dogs or the Supra Collar for Bird Dogs. You can choose either a one dog or a two dog system or if you need to track two or more dogs, see our Maxima Dog Tracking Systems. Tracker Radio offers the world's smallest, lightest and most portable RF tracking receivers. Tracker�s receivers are among the most technologically advanced dog tracking tracking collars on the market, offering reliability, flexibility and portability.