The Seirus Cat Tracks help prevent binding malfunctions caused by wear and gravel contamination of your boot soles. These slip on walking soles for your ski boots are recommended by all major boot and binding manufacturers. In addition to wear protection, they improve traction and provide cushioned walking comfort. These also work well on other types of firm sole boots that have lips on the heel and toe to attach the Cat Tracks. These are pocket sized and slip on the toe and heel (click on inset) of your boots. The sizes shown are men's sizes. If you need to convert from ladies or the cm standard, please see the Ski Boot Sizing Chart .