Your goggles should fit comfortably with your goggle strap over the helmet. There should be no gap between the top of your goggles and the helmets (the so called "gaper gap"). The Sweet Protection goggles ensures a perfect fit to your helmets. The fit might vary depending on the the size and shape of your head, but in general the models Firewall, Interstellar and Clockwork MAX will fit helmets from size M/L and up, while Clockwork will fit helmets from S/M to M/L. For our racing helmets we recommend Clockwork/Clockwork MAX or the Clockwork World Cup models.
For other manufacturers we can’t recommend the best possible fit other than to encourage you to try in store.