Aero helmets are a relatively new addition to the pro peloton, and they polarised opinion from day one.
But love them or hate them, they're here to stay, so we rounded up five of the best in the video below:
Do you agree with our choices? Do aero helmets symbolise progresson within the sport, or are they just an ugly, cynical way to sell more helmets? Let us know in this pro racing thread over at the BikeRadar community.