In a scene that's straight from the cartoons or perhaps a Three Stooges movie, these two try to test the strength of a helmet by hitting it with a sledgehammer. Unfortunately, one of them was wearing it at the time.

Based on the reaction of the man wearing the helmet, I'd say he got his "bell rung" pretty well. On the other hand, the guy who swung the hammer appears to have gotten knocked out so the only thing this test proves is these guys probably have a promising career as crash test dummies.

I don't understand Russian, but I'm pretty sure there were some expletives used in the video.