Booster Straps give you the maximum ski boot performance, extraordinary ski control and shin protecting shock-absorption. Dynamic elastic straps stretch, allowing you to cinch them super tight for an increase in performance. Your stock power strap does not lock you in like a Booster strap for an insanely tight closure. They also provide cushioning to keep your shins from banging when you ski more aggressively. Intermediate strap is (approximately) for skiers from 130-195 lbs that ski at beginner to intermediate levels.