New Balance Men's MT621 Trail Running Shoe 100% Synthetic and mesh Rubber sole N-FUSE is a soft-cushioning foam layered with a firmer structured foam for a midsole with added comfort and support from heel-strike to toe-off AT TREAD is a dual-use outsole tread combining both trail and running lug designs for on and off-road Ghile lacing Ndurance is a rubber compound for maximum durability used in high wear areas