Top Layer is suede material providing comfort and flexibility. The 3 layer heel lift is 3/8" thick. Layers can be removed to meet your needed height. Heel lift fits comfortably in any shoe and comes in three sizes relating to shoe size. Women up to size 8 is a Small width. Women size 8 1/2 and up is a Medium width . Men up to a size 11 is a Medium width and Men's size 11 1/2 and up is a Large width.