I got a shock sensor from my friend and I don't know what the wires go to. It has a red black, blue and gray. It also says mas on the front if that is any help

 

My guess is it is a dual stage sensor, red and black will be power and ground the other 2 leads will be the first and second stage outputs, which is which I do not know but easy enough to find out with a meter.

What alarm are you connecting it to?94

 

Its a crime stopper but I'm adding it so I will have two shock sensors could I just splice it with the original one.

 

Yes you can, if your alarm does not have an "extra sensor" input, remember, if splicing into the "stock" shock sensor leads, you must install diodes on both the trigger leads on both the shock sensors to prevent the sensors from interfering with each other. 94