designed for the office warfare arms race.intended for nerf darts but I measured wrong, then made my own ammo for it.it's supposed to use air pressure, it works decent with a tight seal.you can strap to whatever with zip ties.print, seal with cloth tape or something else for a snug fit. Load with ammo that is also snug fit. Add M3 bolts and rubber bands. put the pin in the small hole as shown in the pic. secure it to something. run your trip line.