Train up to 6 dogs on 1 PRO 70 handheld, up to 3 dogs on 1 PRO 550 handheld or up to 3 dogs on 1 Sport PRO(TM) handheld (additional dog devices required; purchase separately) 1 mile range Built-in BarkLimiter(TM) Remote operation of beacon lights on dog device Interchangeable contact points The PT 10 dog device works with the PRO 70, PRO 550 and the Sport PRO