Hisonic VHF 4-channel Wireless Microphone System with 4 lapels & 4 headsets, HS8100

Receiver: Receiving System: Fixed Frequency crystal-controlled; Sensitivity: 10dB for 60dB S/ N , 4 antennas for each microphone; Audio Output: 25K unbalanced: 0-0.5V/5K ohm, 15KHz deviation; Output Connectors: total 5 1/4" unbalanced output jack, 4 for each channel and 2 combined output; Power Supply: 12V (Separate AC adaptor); Dimensions: 8 1/' (L) x 5 1/2'(W) x 1 1/2' (H) inches. Transmitter: Belt pack type with screw-up plug-ins; Battery: 9V Type alkaline or rechargeable battery; RF Output: 10mW; Nominal Deviation: 25KHz, Max 40KHz; Battery Life: appx 12 continuous Hours for one high performance alkaline battery; Volume control; Power On LED; Battery Low Indicator; Silence circuit eliminated popping noises when the switch is turned on or off; Wide frequency response with low harmonic distortion. System: Operating Frequency: VHF high band, 230MHz to 280MHz; Frequency Stability: 0.05%, crystal-controlled; Modulation Mode: FM; Audio Frequency Responses: 40Hz to 20KHz; S/ N Ratio: > 90dB; Image Rejection: <98dB; Distance: 150 ft in door, 300 ft outdoor. Package Included: 4 VHF Wireless Body Pack Transmitters; 4 Headsets and 4 lapel microphones; 4 individual VHF antennas for each channel; 3 ft 1/4" to 1/4" Microphone Cable; 1 120V AC Adapters (12V DC output); 4 x 9-V (For testing only, you have to buy Alkaline battery for normal use); Instruction Manual.