Removable Insole. Breathable mesh lining. Breathable mesh lining. Protective rubber toe cap 5mm lug depth ; Molded nylon arch shank ; Bellows, closed-cell foam tongue keeps moisture and debris out ;Merrell air cushion in the heel absorbs shock and adds stability Merrell M Select FIT.ECO+ blended EVA contoured footbed with added zonal arch and heel support