Providing sound and long-lasting power for your Alpha T 20 or Alpha TT 25 dog collar devices, this beeper battery pack - with a powerful speaker - helps you keep tabs on your dog in the field. The device attaches easily to compatible dog collars and can be controlled from your Alpha 10/200/300 series or PRO 550 Plus handheld device (sold separately). Select from five sounds - single beep, double beep, triple beep, low beep and hawk - to indicate various movements, such as running or " on point." Manually activate the sound with the push of a button to find your dog when in locate mode. Up to 78 hours of battery life in dynamic tracking mode gives you plenty of juice, so you can focus on your dog instead of the next recharge. Plus, built-in LED beacon lights can be activated from your compatible handheld to help you visually keep track of your dog in low-light conditions. FeaturesBattery life: 78 hoursModes: 3 (run, point, locate)Sounds: 5 (single beep, double beep, triple beep, low ...