what's the best way to detect the magnet? Use anther magnet. But it's not sensitive enough. You have to feel it by youself.Right. This magnetic sensor knows whether there is a magnetic object nearby or not. And it correctly tells you through ditigal output.See below picture for a quick demo!
Wide voltage range from 3.3V to 5V
Standard assembling structure (Times-of-5mm Center distance between two 3mm mounting holes)
Easily recognitive interfaces of sensors ("A" for analog and "D" for digital)