I bought one of these because it's cheap. I can't figure out how to properly mount this thing on my helmet, a Bell Influx. The helmet has a lot of ridges on the shell so as tight as I pull the velcro strap, it still doesn't stay put. Plus the velcro strap doesn't really make sense in the way it threads through the helmet mount. The rubber band strap is not long enough to fit around the helmet, so that's not an option either.

Anyone else have trouble mounting this thing to a helmet, or have any advice? Thanks.