Ideal for athletic events, band practice, field days and more, Half-Mile Hailers carry sound the length of a football field. 50-watt stereo multimedia amplifier with separate tone and volume for line in. Lapel microphone and wireless receiver lets you roam within a 300-foot radius. Features 3 mic inputs: dynamic, condenser and wireless. Use up to 4 microphones for multiple presenters. Tapered weatherproof horn allows maximum sound penetration. Also includes built-in tripod mount. Dual wireless possible with optional wireless mic kit, allowing 2 people to be wireless simultaneously. Runs on 10 "D" batteries, sold separately.