The front guard fits again with zipties to the fork legs and arch (or in my case the crown of my rigid forks) and goes a long way to stopping the mud that is thrown forward from the tyre and back into your face.
Both guards can be fitted with "extenders" if you feel there isn't enough coverage. I found them both fine as standard. These aren't like road bike guards though, so if you are expecting to get no mud on you at all then you'll be disappointed as of course they only cover half the wheel, and mud will find its way onto the seat tube of your bike, BUT having a dry backside is so much preferable and comfortable than muddy legs, there is nothing worse than riding for hours with wet shorts!
the proof though is in the pudding though and after a two hour ride in the tail end of hurricane Bertha my shorts looked like this