Feature: 1. Each pager builtin rechargeable lithium battery, low power indicator and charging indicator2. Support learning code registration mode, you can easily up to 999 pagers3. Have two remind mode of vibration and buzzer, each mode is accompanied by LED flashing4. Equipped with up to 20 battery charging slots, greatly the work efficiency and avoid the in a long queue5. External antenna support about 1000 (3280ft) working distance in open area. Widely used in fast food restaurants, food courts, pizzerias, churches, car shops or other where many customers are for serviceSpecification:Item Type: Wireless calling systemPager Frequency: 433MHzReceiving Sensitivity: -107dBmDecoder: Learning code (AM)Standby Current: 10mAWorking Current: 75mA (vibration) Battery Capacity: Built-in 200mAh rechargeable lithium batteryCharging Voltage: DC 5VKeyboard Call Button:Frequency: 433MHzStandby Current: 24 mATransmission Current: 100 mAWorking Voltage: DC 5V or 2.5A power adapterKey Function:Power or Reset: Long press for 3 seconds to turn on or off short press to reset to standbyCode Recording: Long press for 3 seconds to enter the code recording stateMode: Switch the remind mode, dial up for vibration mode dial down for vibration and buzzer modeKeyboard: Press 0-9 digits to select the number you to call: 1-999, then press the "call" key to call. If the wrong number is , press the "clear" key to reselect the number.Plug Type:US Plug,it applies to Canada, ,Mexico, Thailand, the , the Philippines,Taiwan and so on.Voltage: AC110VMaterial: plasticcolour: blackPackage Contents:1 x Transmitter20 x Receivers1 Adapter1 x English ManualOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is 1-3cm.