How to work of waiter calling system

When the guest need any service, they can press the call button on the table, the table number will be showed on the RECEIVER of watch or display screen with clear “dingdong” sound or vibration, then the waiter could offer service very timely.

Specification of wireless call button

4 key: Call, Bill, Drink, Cancel                                          
Signal Distance: 200M in open area   
Material: PC and waterproof silicone
Dimension: 60*60*20mm
Table or wall-mounted installation              
With a 12V 23A battery
Any language any logo is acceptable

Table call button need work with wireless receiver