Thanks to TagFerret, co-inventor of LTTO gear, we got specific instructions on how to turn the Thunder Pack from a thing that shakes when you fire AND when you're hit, to a thing that only shakes when you're hit! This one is even easier than the Virtual Scope mod. Just open up your Thunder Pack, locate the brown wire in that bundle, and snip it! Note that the wire color might change. Make sure that the wire you snip is the one that goes up to the top of the panel, kind of by itself. You can kind of see that in my photo. Put it back together, and now you have a Hit-only Thunder Pack. Be sure to mark it when you're done so you know that it will only rumble when tagged. Some people like the firing rumble. Anyway, in the photo above, you can see the wire bundle before, the brown wire being snipped, and the wire bundle after, with the two ends of the brown wire crossing each other as they naturally will after getting snipped. I'm not sure if this Thunder Pack was already less strong than another one I was testing, but it seemed to be very slightly weaker than the other one. Not that it matters, since if you feel it shake, you just got hit. It doesn't matter how strong the shake is. ;-)