It's a Staplex SJM-1, it was acquired from a former employer that was throwing out everything. The camera I'm using doesn't really capture well, you can see that even though I have lots of light, the performance on video is still kind of crap. It makes a nice satisfying clunk that flickers the lights when it fires, and there's a nice green spark inside. I tried to capture that, but I suspect my camera isn't fast enough. I have a better camera but it needs a new battery. If I can get one, I'll try again.