EASY TO USE: Securely installs to the exterior of the helmet within seconds and is easily removed when riding conditions are such that additional ventilation is desired. WEATHER TESTED: The Aeroshell snaps into place to create a barrier from the elements and keep you warmer and drier while still allowing for air movement to pass through PERFECT COMPATIBILITY: Designed to fit perfectly over specific models of Lazer helmets and does not interfere with the exterior size adjustment. SUPREME AERODYNAMICS: By closing off the ventilation holes, the amount of aerodynamic drag the helmet creates is strongly reduced, making your road helmet into an aero helmet. COMPACT DESIGN: Rolls up and fits in your jersey pocket when not in use. Keep the rain, snow and mud from getting inside your helmet, or use as a quick aerodynamic solution to close off the front and side vents. Aeroshell is a great accessory for compatible Lazer helmets!