The 2.0 upgrade of the Mugen Tech Lace includes Mad Rock's new proprietary material called the Power Flex Upper. It is a fusion of 2 way stretch brushed polyester and their Science Friction 3.0 rubber formula. The end result is a material that is super sticky, sensitive, comfortable, and envelopes your feet like no other climbing shoe before it. The new progressive angle 3D molded heel cup hooks, smears, jams and locks better than any other heel design out there by using only Science Friction 3.0 climbing grade rubber formula. A synthetic upper keeps this vegan friendly shoe from stretching out. The hemp foot bed is inherently antimicrobial and antibacterial which keeps the shoes smelling fresh. Mugen Tech Lace 2.0 is Mad Rock's high performance all around shoe of choice that every climber should have in their inventory. Keep um' laced.