According to the status of the device indicator, you can determine the reason and solution for the failure of the distribution network, please correspond one by one. 1. Before adding a device, make sure that the device is in the red light flashing state slowly (twice per second), if the indicator light is abnormal, please restore the device to factory settings (long press and hold the reset button of the device until you hear a beep sound. let go). 2. The device does not support 5GHz WiFi, please make sure that the phone is connected to 2.4GHz WiFi when adding the device. 3. The WiFi password must be entered correctly, paying special attention to complex special characters. 4. Note that the current WiFi network is smooth, it is recommended to restart the router and try. 

The card can also be used on a mobile phone. It is generally recommended that a special card be used exclusively. Unless the camera is broken, the card can still be used. 

It's better to buy a cleaning fluid for lens filter. 

I don't see why not, remember that the filter goes on the lens, not on the camera. 

This filter will fit any lens with a 49mm filter thread