Fashion watch design,Wireless technology,Millions of groups learn to code,Low voltage indication.Built-in removable, rechargeable lithium battery,Intelligent code, easy to use and simple Suitable for the elderly, the disabled, hospitals, nursing homes, restaurants, kitchens, factories and other call ..This series of products are widely used in restaurants, bars, teahouses, hospitals, nursing homes, beauty salons, factories, hotels, residential offices and other service places. The product features excellent, rechargeable battery power, long standby time, with perfect charge and discharge protection circuit; With automatic. detection of battery capacity function. When receiving the wireless call signal,the machine send out vibration, buzzer, and flash. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:Photo Color Material:ABS Package Contents: 1x Wireless Pager 4x Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.