~~ Topo says~~

Discover comfort worth sweating over with the fourth generation of our best-selling trail runner. Ultraventure 4's plush platform combines with our signature roomy toe box to deliver long-lasting comfort, while the ZipFoam™ midsole offers lightweight response. Our Vibram® XS Trek EVO outsole offers excellent multi-surface traction, with a lug pattern and depth optimally designed for light to moderate trails and for easy trail to road transitions. The recycled mesh upper features a fresh look, now with strategically placed PU print for added structure and durability.