Product function 
1.Power on and power off 
Long press (left hole) to power off; and short press to power on. 
2. Function 
1. Remind period: short press (middle hole) the "function" key once to add 10 seconds, the longest period is 50 seconds. 
2. Code: long press (middle hole) the function key, when the two indicators lights, press the corresponding numbers 1-18. 
3. Remind model 
The "remind model" is the vibration in short press (right hole), and press again "bell and vibration" model. 
4. Advertising size in extension: 37mm*84.2mm.  
5. One button to turn on/off the host: debug the18 extension boards to plug in the charge stand of the host, operate when powering on: long press the 18/36/54 button of the host for 3 seconds, the power will be shut off; press any key to power on. The operation is simple and more convenient. 
Usage 
Place the self-help meal/queuing system products in the front desk or queuing service center, and distribute it orderly, 
for example: distribute the No. 1 card to the customer, at the same time inform the customer to wait at the gate of the hall to take food or seating position; 
at this time, inform the desk staff to long press the corresponding key of No. 1 card, then the customer's card will prompt by warning tone, 
flashing light and vibration, the customer can immediately be arranged seat by the service staff, and the service staff should take the card back 
and plug it into the charging stand for the next round of service.