Protect your home or business from unwanted intruders with a pneumatic cannon that shoots water-filled ping pong balls capable of tearing holes through various materials. That, or shoot regular air-filled balls at your friends and family, leaving hilarious-yet-playful welts.

Built by Ron Kessinger and shown off at a recent maker meetup in Denver, the potentially deadly apparatus looks like the bastard child of a telescope and a harpoon gun.

As if it needs to be said, DON’T TRY THIS AT HOME. Unless you have access to a standard wall socket and a compressed air line, plus all the parts needed to build one of these. In that case, have fun this weekend.

Lethal Pneumatic Ping Pong Ball Gun [TINYenormous via MAKE]