Black Diamond Custom Plastic 4 buckle Ski Boots with power strap, with insulated form fitting inner boots that use a Boa lace system, walk/ski mode heel lever, and 30.5 Men's/Unisex Mondo Point sizing (US 12-13 size). These are stiff plastic power transfer boots that maintain excellent ski edge in any condition and especially at high speeds! The inner boots remove from the outer boot shell and can be worn around base camp. The inner boot is insulated with form fitting foam to protect your feet from the cold and are comfortable for all day skiing!