From the manufacturer

The new 4-Quattro Pro is the lightest weight, most powerful boot in its class. A new reinforced cuff works in conjunction with our Alpine Axial system providing a precise, high-performance alpine like fit. Our new Secure Speed Lock4 provides extra piece of mind and security when charging down a couloir, all while still providing 60° range of motion for long days on the skin track. Whether you're ripping bell to bell laps at the resort or on a mission deep in the backcountry, the 4-Quattro Pro was purpose built for free rides in search of the steepest, most challenging lines on the planet.

Features

• Ski Walk Mechanism
  Secure Speedlock 4 Mechanism, provides a secure and powerful dual lock for extra security to tackle any kind of descent. 
• New Reinforced Cuff
  New cuff with rigid structure in the back, and lowered at the front for faster transmission of impulses and energy from skier to ski. 

Specifications

• Size Options: 24.5 - 33 (half sizes)
• Liner: Intuition® Pro Flex Ride
• Shell: Pebax® Rnew®
• Closure: 4 Buckles + Booster® active power strap
• Binding System: Alpine GripWalk + AT + TLT
• Weight Reference: 1555g; 3lb 6.08oz (27.0)
• Last: 100mm
• Cuff: Pebax® Rnew®
• Flex: 130+
• Waterproof/Breathable: PFAS Compliant
• Outsole: PRESA® SKI-01
• Tongue: Pebax®
• Ski/Walk Mode: Secure speedlock 4