Features:1. 20 Channels - A 20 channels base and 20 pieces of pagers help avoid the waiting of the client in the long queue to a great extent.2. 20 Charging Slots - Pager can be placed in the base to charge when it's free.3. 1km Connection Distance - A built-in antenna enables pager to work normally within 1km from the base.4. 3 Indication Modes - Adopting 3 indication modes of vibration, bee cue, and vibration plus bee cue to make it suitable for different situations.5. -107dBm High Sensitivity - High sensitivity enables base to call pagers clearly and correctly.6. Wide Compatibility - Suitable for places where there are many guests waiting for service. Specification:Product type: Wireless Queue Calling SystemChannel: 20 channelsIndication mode: Vibration, bee cue, vibration plus bee cueReceiver: Working voltage: DC3.7V (rechargeable battery)Charging voltage: DC5VWorking frequency: 433.92MHZStandby current: 1010mAWorking current: 7510mA (vibration)Receive sensitivity: -1072dBmBattery capacity: 200mAhDecoder: Learning Code (AM)Size: about 49*101*11mm/1.93*3.98*0.43in20-way Keyboard Host:Working voltage: DC5V/3A power adapterWorking frequency: 433.92MHzStandby current: 245mATransmit current: 10030mAEncoder: Learning Code (AM)Size: about 150*300*33mm/5.91*11.81*1.3inPackage List:1 * 20 Channels Main Engine20 * Receivers1 * Antenna1 * Power Adapter.