This thing is absolutely mandatory if you ride during winter. I'm not sure what kind of black magic is actually at work inside it, but it got completely rid of that fog that had been bothering me since the temperatures dropped. Installation is pretty straightforward. Just make sure you don't touch the fog absorbing part with your fingers. Also: make sure you're getting the right model for your helmet. For example, this fits a RF-1100, which has a CW-1 shield, but might not work on other helmets.