5pcs SW-420 Vibration Sensor Module Vibration Switch Alarm Sensor Module for Arduino

You can adjust the sensitivity, but it seems to lean hard toward the extremes. Just tapping a solid surface can set it off, which I love.

Very good. Very sensitive but not too much false alarm. Sensitivity seems responsive to adjustment. Overall very good device and value.

Device does what it should, the adjustment is VERY sensitive. Signal is very brief, but if you’re looking for a quick trigger DO, this does the job

This works great with arduino and esp products.

I have gone through the hole pack trying to find one that will work consistently. These things are for detecting small vibrations like tapping a finger at one side of a table with the sensor on the other end. The problem I had is they often get stuck in a high state (vibration detected) for minutes on end - in other words if they are perturbed they will register the vibration and go high, but stay high even after all vibration from the system has dissipated. The only way to get it out of the state is to give it another tap/knock. In order to reduce false positives I use two of them and read them back to back (not that simple: involving other logic very specific to my application that gives me only 80 percent accuracy). But really the device has such low fidelity that it is useless for most applications. You can use them in like a "mouse trap" type scenario where you want to measure a vibration event once, but after that vibration is reported you can no longer trust further reads of output of the device as it could be just stuck high.