Propet Walking Pro Orthotic Insole Synthetic Imported Synthetic sole Top layer made with memory foam to mold to the foot for the perfect fit 3 by 4 length semi rigid orthotic in between the top and bottom layers to reduce arch strain and discomfort and improve lateral stability Extra cushioned bottom layer adds exceptional shock absorption and delivers superior compression set performance to help retain shape Soft, breathable nylex fabric sock liner features a perforated forefoot to keep feet cool and dry Anti microbial properties fight the growth of odor causing bacteria and fungus