Features Piezo Dynamic Technology that delivers powerful performance while significantly reducing weight & increasing battery life. Full frequency response provides clear, intelligible amplification. Adjustable volume & three modes (talk, siren & whistle) offer enhanced versatility. Battery indicator light vividly shows power status. Weatherproof design stands up to inclement weather. Pistol grip & wrist strap make it comfortable to hold. Audio Range: 0.62 mi; Diameter: 7.75"; Length: 12"; Maximum Battery Operation Time: 18 h.