Castelli summer head bandthe castelli summer headband is the perfect under helmet addition for those hot summer rides designed to be a wicking layer the castelli summer headband will soak up the moisture and avoid the problem of sweat from dripping down onto your face and eyes when riding featureswicking layer to keep sweat out of your eyesmesh panel construction for ventilationfits under helmetbuy castelli clothing from chain reaction cycles the worlds largest online bike store