vibration sensor magnetic

Welcome to CE dmsherazi,
Can you state your points clearly so that other CEans can help you? Meanwhile have you tried attaching some links which would be useful in your explanation of your question?

sorry for the bad quality of snaps, i will post new here
this is for alarm systems, its used to check if someone try to hit the door or try to open it forcefully... the spring is the same as described by Steve

the blue thing is a two terminal package for a coil, i had tried to tear open one and its just a coil wound on a plastic core. the concept is that the spring has a permanent magnet on it, when there are vibrations the spring makes the magnetic field to vibrate that induces some current in the coil, the signal is then amplified and through comparator fed to relay....

this is marked L1 that means its an inductor, but i am just wondering if there is a pair for magnet value and the inductance value for optimum results, or is it just a separate inductor,

how can i get optimum results?

I don't know whats the function of this thing but you can use Accelerometer for vibration measurement.