When we are looking for a boot that thrives on the foot of quickly-growing skiers we always take the K2 Reverb Ski Boot into consideration. The 70 flex encourages proper technique with easy manipulation and enough stability for hard charging. Meanwhile, the lower cuff on the timeless 2-piece, 4-buckle design allows newer skiers to experience the control and power of an adult boot without tossing skiers straight into the deep end.