The D.T. Systems BTB Series give you the ability to keep track of your dog's location when he is out of sight and lets you know when he has gone on point. The use of both the sound booster element and the long duration, double beep make the BTB 809 collar much easier to hear at long range. (Actual yardage will vary depending upon the relative position of yourself and your dog and other variables such as cover and wind speed and direction). The BTB series is completely waterproof and uses rechargeable batteries (batteries and charger included). FeaturesEasy Operation - One touch push button systemLong Range Audibility - Audio booster elementReliability - State-of-the-art microcomputer technologyTwo Operating Modes - Run/Point, or Point onlyRechargeable Batteries - Charger includedCompletely Waterproof