With the introduction of of the Rottefella XP binding and the ideal match of the Alpina Alaska XP boot a decades long argument has closure. For backcountry ski touring the post-ski discussion has been, 75mm boots have better downhill control, but NNN-BC tours better. 75mm boots walk and climb better out of the binding but NNN-BC has more durability. No more discussion. Compatible only with the new Rottefella Xplore binding, now you can go backcountry skiing with more downhill control, a vastly better touring stride, bombproof boot/binding integrity, and when off the skis not tripping over that stupid duckbill or digging out gravel from the binding channel. Compatible only with the Rottefella Xplore binding Weighs 20% less than the regular Alpina Alaska BC The rotation point is moved back close to the foot for a better stride SpringPin Technology removes the risk of snow packing, provides comfort, stability and mobility and allows the user to step-into the binding wit