Aero Tech Designs Neoprene Shoe Cover - Hi Viz and Black Neoprene Elite water barrier neoprene shoe covers; 3mm neoprene thermal insulation; taped seams to enhance thermal insulation High cuffs to extend over your tights and protect your full leg from the cold and provide insulation between shoes and tights Size Chart: Small = Euro 40, Mens 6.5, Womens 6-8 | Medium = Euro 40-41.5, Mens 7-8, Womens 8.5-9.5 | Large = Euro 42-43, Mens 9-10, Women 10-11 | X-Large = Euro 44-45, Mens 11-12 | XX-Large = Euro 46-47, Mens 13-15 Reflective tabs to increase visibility in low light; reinforced soles for walking and durability off the bike; large cutouts for cleats and shoe heels Velcro closure at ankle, easy on and off with YKK Vislon zipper, available in 2 colors: Black and High Viz Yellow 3mm neoprene thermal insulation High visibility safety yellow nylon surface Easy on and off with YKK Vislon zipper High cuffs provide insulation between shoes and tights Reinforced shoe soles for walking. Velcro closure at ankle Reflective tabs show as a bright moving part in low light environments. Insulates to keep feet warm while cycling in the cold. <span class="a-text-bold">Wind-resistant</span> - Barrier reduces wind to keep you warm yet not clamy because it is breathable. <span class="a-text-bold">Breathable</span> - Wicking Polyester fibers pull perspiration into the surface for evaporation and Insulation. <span class="a-text-bold">Durable</span> - Fabric is rugged yet delivers soft feeling comfort and warmth. <span class="a-text-bold">Body</span>: 100% polyester and 3mm neoprene thermal insulation with a nylon face fabric. <span class="a-text-bold">Function</span>: Neoprene Cycling Shoe Cover insulates feet from the cold while cycling.