Well, we have a couple of these (http://www.leaktools.com/products/listening_devices/geophone.php), one of which is broken and will soon become a science experiment for me. The one I'm looking to get fixed is more like the other two shown on this page (http://www.leaktools.com/products/listening_devices/). So, I figure I'll try this company out and see if they can work on them.