Description: This system has a qualified speaker and high-sensitive microphone. The voice is clear and natural. Suitable for many occasions. Features: Equipped with recording jack, the two-way voice signals can be output easily. (such as the bank teller system for recording) Aluminum alloy panel and simple installation make it a great option for communication. Qualified speaker and high-sensitive microphone, the voice is realistic and clear. Suitable for many occasions like bank, securities, hospital, bus station, etc. Volume of speaker and sensitivity of microphone can be adjusted. The inside and outside speaker can be turned off individually. Both inside and outside have speaker and microphone. Specification: Brand: Retekess Material: Aluminum Alloy Connection Cable Length: 2m / 6.5ft Working Voltage: DC 9V / 300mA Adapter: AC 110V or AC 220V, 50/60Hz Main Sound (sub sound): 2W+2W Microphone Sensitivity: -48db 20Hz-16kHz Size: 150 * 100 * 50mm / 70 * 20mm Weight: 350g / 0.77lb Package Includes: 1 * Dual-way Intercom Mic 1 * Speaker 1 * Power adapter 1 * English manual