?This SY601A11 2.4G Digital Wireless Non-visual Intercom System Door Bell adopts 2.4G ISM digital frequency hopping and encryption technique. Its transmitting power is less than 100MW. Besides£¬ it adoptsAFH adaptive FM technology to ensure powerful function. This digital wireless door bell featuresstrong communication confidentiality£¬ clear voice£¬ wireless remote unlocking£¬ energy-saving and longcommunication distanceadvantages. 2.4G wireless digital transmission intercom signal is stable and strong to make sure excellent communication effect. It is easy to install without arranging wire. This product is suitable foroffices£¬villas£¬ courtyard and unit family etc.                                    Features            Adopt 2.4GHz ISM digital frequency hopping and encryption technologyBarrier-free communication distance is up to 300 metersFine anti-interference ability and clear soundOutdoor unit adopts touch button£¬ power-saving£¬ generous and elegantWith rain-proof cover to protect its lifespanHandhold indoor unit with exquisite base is beautiful and practicalIndoor unit features ring reminder and flash reminder for deaf or dumb people useIndoor is designed with unlocking button£¬ support wireless remote unlockBoth indoor and outdoor unit use the high capacity BL-5J lithium-ion rechargeable batteryOutdoor unit supports 2 ways unlock mode: power-on unlock or power-off unlockOne outdoor unit is able to simultaneously match with 3 indoor units                                                            Specifications            Material    ABS    <br>Working Frequency    2.4KHz    <br>Battery Work Voltage    3.4V-4.1V    <br>Battery Charge Voltage    5V    <br>Battery Charge Current    200mA (TBD)    <br>Indoor Unit Standby Current    Approx 2mA    <br>Indoor Unit Work Current    90m(TBD)    <br>Outdoor Unit Standby Current    approx10mA    <br>Outdoor Unit Work Current    110mA(TBD)    <br>Work Temperature    -10-70 Degree    <br>Work Frequency    2400MHz-2483MHz    <br>Transmission Power    18dbm(TBD)    <br>Sensitivity    -90dB    <br>Remote Distance    300m    <br>Audio Rate    16K    <br>Audio Digits    16 Digits    <br>Time Delay    Approx 16m/s    <br>Total Harmonic Distortion    -60dB    <br>S/N Ratio    90dB    <br>Frequency Response    500Hz-10KHz    <br>Working Temperature    -20-60 ¡ãC    <br>Indoor Dimension    (5.91 x 3.74 x 2.17)" / (15.0 x 9.5 x 5.5)cm (L x W x H)    <br>Outdoor Dimension    (6.69 x 1.97 x 1.18)" / (17.0 x 5.0 x 3.0)cm (L x W x H)    <br>Weight    15.87oz / 450g    <br>                                                            Package Includes            1 x Indoor Unit1 x Outdoor Unit2 x Batteries (BL-5G)2 x Chargers1 x Manual1 x Screw