Merrell Vapor Glove 6 Running Shoes Merrell's leadership in the barefoot category continues with the Vapor Glove 6. These are the most minimal shoes Merrell creates, featuring a Vibram EcoStep outsole that wraps the foot to maximize grip and connection and a breathable mesh upper to keep feet cool. Recycled Mesh Upper The upper is constructed with 100% recycled mesh for optimum air circulation and ventilation, meaning your feet can breathe. A lining made with 100% recycled mesh allows for temperature and moisture control by allowing heat and moisture to escape, and move to the outer of the shoe - keeping your feet feeling fresh and breezy. Merrell Barefoot 2 construction is designed to keep the foot in a natural position, with zero drop, to encourage natural running form. By hitting the ground with your forefoot, rather than your heel, your speed will increase and your likelihood of injuring your joints will be lessened. A bellows tongue features on the upper to help keep out de.