The Comp was Sidas’s very first PU liner. Strong, an excellent fit, with foam tongues: the ultimate liner for competitive and racing skiers. The basic principle of boot fitting is that you fit the smaller foot and then change (widen, lengthen) the plastic shell of the boot to match the bigger foot for a permanent solution. Boots can never be made successfully smaller by adding padding. It will always compress and pack and it’s difficult to tell if you got the right amount in the right spot. Custom foam liners offer the best solution, providing the exact match or mold for both your feet.