Restaurant Pager System with 16 Pagers Wireless Queue Calling System. No more waiting in line:Just easy to do the business with this calling system! Customers come to the restaurant and make an order will get a receiver with corresponding number from the waiter. When the order is ready, the waiter at the counter will press the number on the keyboard. The corresponding guest gets the wireless signal by his pager vibrating or LED flashing or sounding, then he knows order is ready and goes to the counter to take his food. How to add more receivers: Step 1 : Insert the receiver into charging slot, long press the [power] key for 3 seconds, three red LED light will be keep on mean enter registration state. Step 2 : Press the keyboard corresponding to the number, then press the [CALL] key, receiver buzzer two times mean registration success, short press [power] return to standby state. Features 10 charging slot Receiver power indicator, low-battery alert. The host password protection to prevent error Settings Super receiving sensitivity Self testing while power on. One key call all receivers. One-key turn on/off Charge without heat Keyboard call host. Working frequency : 433.92 MHzSupply voltage :Input :AC 100-240 V Output :DC 5 V/5 AStandby current : 10 m ATransmit current :100±30 m ASize : 9.2*6.2*1.3 for Receiver Working frequency : 433.92MHzSupply voltage :DC3.7V (Rechargeable battery)Charge voltage :DC5VStandby current :