How much does it cost to install an office wireless surveillance camera with a telecom 4G card?

Wireless over 500 yuan does not need telecommunications, as long as you are a smart phone and the office has a wireless network. Functions include: you can watch the office remotely with your mobile phone, you can control the camera to rotate left, right, up and down to achieve no dead angle, you can make voice calls with the monitoring camera (like a walkie-talkie), and you can turn on the infrared probe to give an alarm. If someone breaks into the office, the alarm will sound and the mobile phone will call the police.