[Full duplex intercom technology] Deshun Window two-way intercom DS-989 adopts full duplex communication technology to meet more office needs, and full duplex means that two-way signal transmission (A→B and B→A) can be carried out simultaneously (instantaneous). Refers to A→B at the same time B→A, is instantaneous synchronization, just like A car two-way street, and the traditional window walkie-talkie is A one-way street, only A→B or B→A. [Internal and external one-click closing function] Deshun window two-way walkie-talkie DS-989 adopts all-metal body design for better durability. It not only has the function knob to adjust the volume, but also adds the internal and external one-button sound off function, to achieve internal and external independent volume control, reduce unnecessary mutual interference. [Split microphone] Desun window two-way intercom DS-989 microphone adopts detachable design, the microphone also uses a halo when working, full of advanced sense, and the microphone coil has been upgraded, the anti-interference ability is stronger, to avoid screaming at the same time, but also to ensure that the sound is more clear and natural, and the sound quality is better. [4PIN interface/Support for external devices] Deshun Window two-way walkie-Talkie DS-989, 4-PIN interface is more firm and not easy to fall off, in addition to support recording function, you can also connect external microphone devices. [Wide range of application scenarios] Deshun Window two-way intercom DS-989 is suitable for the medical field, bank window, hospital window, post office window, securities window, embassy visa office, securities company, scenic ticket office, station, restaurant and other places, Deshun, so that communication is more convenient.