Klim Krios Helmet Liner Defeat the grunge with these replacement liners for your Klim Krios Helmet. Liner is interchangeable within shell sizes: Sm-Md, Lg-3Xl. If you'd like a more snug fit, order the liner in your shell size one size down from your helmet size e.g. if size MD is too loose, order the size SM liner. If you'd like a looser fit, order the liner in your shell size one size up from your helmet size e.g. if size LG is too snug, order the size XL liner. Features: Easy to install Moisture wicking