pro tongue mvPRO TONGUE liners are the first tongue style liners Intuition created that can compete with the Power Wrap in stiffness. Theyre ideal for most shells used by intermediate and advanced level skiers and riders. This high density, medium thickness liner features a 2mm Strobel sole, with removable 7mm foam insoles, and a roomy toe box to accommodate various foot volumes and widths in tighter fitting shells.