The main upgrades include: all frequencies are generated by a single chip microcomputer, which improves the stability of frequencies and product life, and upgrades the timing function and power indication function. The timing time defaults to 30 minutes and can be customized. The power indicator led lights up when the battery voltage is about 7v.
主要升级的内容包括：全部频率由单片机生成，提高了频率的稳定性和产品的寿命，升级了定时功能和电量指示功能。
定时时间默认30分钟，可以定制。
电量指示led在电池电压7v左右时点亮。