Shaft Height: Approx. 16'' Tall. The Alpha Aggressive features an extremely durable Vibram outsole for superior traction for any outdoor conditions. Long-wearing, comfortable, lightweight and 100% waterproof, the boots are made with Alpha construction, which consists of ozone resistant rubber over 3.5mm naturally insulating neoprene to keep feet dry and comfortable. The non metallic safety toe meets. Mud Lite outsole provides superior traction with a low profile 90º heel, unique multi-directional lug pattern, and an oil and slip resistant rubber compound.