● 小巧轻便，方便安装；
Small and light, easy to install;
● 使用寿命长；不换电池 3 年以上；
Long service life; more than 3 years without changing the battery;
● 识别距离远，灵敏度高。
Long recognition distance and high sensitivity.
● 内置可更换扣式 CR2477 电池一颗，工作电压 3V；
Built-in replaceable button type CR2477 battery, working voltage 3V;