Replace your S1 Lifer Helmet Sizing Liners with some fresh ones! The S1 Lifer Helmet Sizing Liners are replacement front and back pads for the S1 Lifer helmets. These Liners are compatible with all of our Lifer Helmet Shells including our standard Lifer, Mini Lifer and Mega Lifer. For a complete breakdown of our helmet sizing go to our How to Measure Head for a Helmet Page,