SU-668 has five unique circuit board chip protection functions: overshoot protection, overdischarge protection, temperature protection, short circuit protection and voltage protection. Fully manage the battery, intelligently allocate fast charging and continuous charging, and extend the battery endurance and battery life while cycling charging and discharging. The intelligent control chip is used to control the input voltage, and the accuracy of the input voltage is always maintained to plus or minus 1/1000. Avoid battery life shortening caused by voltage fluctuation. Automatically detect the battery voltage, when the battery is fully charged, automatically cut off the input voltage to avoid the danger caused by overcharge of the battery. The receiving distance of the partition wall is 50-100m. Open receiving distance is 1500 meters. Tips: The distance is too far to reach the additive signal intensifier. Thanks for choosing the queuing wireless calling system. It adopts RF wireless technology with millions of different learning codes. The system includes 999-channel call keyboard and portable buzzer& vibration receivers. Each receiveris rechargeable and And it has a number. In standby status, Superposition of charging. while the client places an order, he(she) will be dispatched one receiver with a number, when the order is ready, press the keypad to call the number, the client will get it through the buzzer/vibration/LED indications. The queuing system greatly improve the work ef ciency and avoid the client waiting in a long queue. It is widely used in fast food restaurant, dessert shop, Coffee house, Pizza shops, auto 4S shop or other queue occasions. Why you use? Minimize crowds in waiting ling Reduce staff chaos & improve amdience Notify people faster Improve work efficiency Enhances the restaurant's inage