The perennial, top-of-the-podium boot in major skimo races across the globe, the Alien 4.0 represents the pinnacle of lightweight ski boot engineering. The shell and cuff are crafted from hand-laid carbon fiber, providing ultimate strength and stiffness at a ridiculously low weight. The speed Lock Lite ski-walk mechanism is integrated with the cuff closure via a Dyneema cord, for quick, single-action transition. The BOA Fit System floating closure is located under out Light Shield Tech gaiter, ensuring quick, easy and secure fit transitions. The Vibram outsole ensures traction on the snow for mandatory boot pack sections. When low weight, high speed and ultimate race performance are your priorities, reach for the Alien 4.0.

Carbon Fiber Cuff: Hand laid carbon fiber cuff for the ultimate in lightweight rigidity, with Pebax overlapping front panels for a contoured closure
Carbon Fiber Shell: Hand-laid carbon fiber shell is super stiff and crazy light, with a protective toe cap
Speed Lock Lite: Simple and secure, with 4 forward lean positions, the Speed Lock Lite ski-walk mechanism is strong and reliable on the downhill and fast on the transitions due to a single action Dyneema cord that closes the cuff
The BOA Fit System delivers micro-adjustable, precision fit engineered to perform in the toughest conditions.
Vibram UFO Sole: Made with TOP85 compound that offers great durability and grip in cold conditions

FEATURES
Feature Details
BOA FIT SYSTEM
The patented BOA Fit System consists of three integral parts: a micro-adjustable dial, super-strong lightweight laces, and low friction lace guides. Each unique configuration is engineered for effortless precision delivering a connected, fast, customized, and durable fit, and is backed by The BOA Guarantee. The Alien 4.0 system is mounted to a protective Pebax tongue panel and compresses down on the instep as it