VocoPro UHF-5800 Professional 4-Channel UHF Wireless Microphone System Type: Wireless Microphone Systems Specification: Receiver Oscillation Mode: Quartz Controlled Fixed Frequency Receiver Stability: 10 PPM Receiver Max. Deviation Range: 50Hz Receiver S/N Ratio: >105dB Receiver T.H.D.: Outputs: Mic Output x 4 Sensitivity: Receiver: 1.6uV @ sinad =12dB Power Supply: Receiver: External DC Power Supply, 0.7A, 12~15V DC Microphone: 1.5V AA Battery x 2 Battery Time: Up to 12 hours Dimension: Receiver: 18.9 (L) x 1.8 (H) x 7.8 (D)