Fits most helmets, hard hats, cycling helmets, etc., In hot weather, bucket hat, cup are also usable! The hose can be cut to fit the shape without confusion or interference. It has button to quickly clear the water vapor. The wind speed is adjustable for different of use. Besides DIY goggle modification, its hose pipe diameter is also designed to be compatible with modification frame like Airflow Gasket. This anti-fog goggle fan is designed to effectively remove moisture and has a cooling function, it allows the temperature of goggles to remain constant with the outside temperature, preventing condensation. Removes moisture in the summer and balances the temp diff inside outside of lens in winter, reducing mist condensation. Keeps your vision clear and focused at all times.