There are so many things you can do with 550 cord: make a snare, build an improvised hammock, replace your shoestrings, even floss your teeth. But use it to whip a 100-mph golf ball at your buddy’s testicles? That’s one we’ve never thought of before, and we’re assuming most people — or at least, most sane people — haven’t, either.

But of course our ingenious friends over at Ready Man have. And, fortunately (or unfortunately) for the rest of us, they’ve just released this DIY video that features MMA legend Jeremy Horn demonstrating how to build a testicle-destroying 550 cord combat sling in a few easy steps. Then, his pal takes one to the nuts. It’s like Martha Stewart Living, but for sadists.

Just remember: knowledge is power, and testicles, whether they belong to you or someone else, are crucial to the propagation of the human species. Maybe aim for the squirrels instead.