RSD INTERNAL RAIN SOCKFor those who are doing a lot of wet weather riding we recommend RSD's Internal Rain sock. While not a necessity for riding in the rain with an RSD air cleaner, it can help reduce filter saturation. The Internal Rain Sock is compatible with all RSD Venturi and Turbine air cleaners. It is made from a durable polyester material that has been factory treated using a hydrophobic process to repel water and it does not effect performance.