Excellent quality, especially for the price I paid. I use them for MTB'ing and they fit well, are very comfortable and secure. I used them without the strap to keep them on my noggin and they stayed put throughout a demanding 3 hour ride.
I had no problems changing the lenses, a simple snap in and out. The options of different lenses should suit just about everyone. The only issue I had was they steam up quite quickly if you ain't moving too quickly. They need airflow to allow the vents at the top to work adequately. Simple answer though, don't stop!
A good purchase if you ride bikes, to stop flies, mud, etc., damaging your peepers.
Well recommended.