The model is effective, but the distance is not advertised good, do not expect more than 150 m up to remind your dog because after he realizes that he does not risk anything. The necklace has a very long battery life (another brand had to recharge every night!), The French record is obviously incomprehensible and must bring the Harrap's to understand the functioning of the machine but after that is to very simple. It is actually waterproof (but I will not try seawater). Tip: Do not expect your dog to be too old for the package, it will be much faster.