Boot Mountain Horse for kid . Built-in waterproof and breathable socks” keep feet dry. Heat insulating Thermolite lining. Rugged Duralon shaft for long term wear. YKK Vislon back zipper for easy on and off. Waterproof foot bed up to YKK Vislon zipper. Removable “fur” insole for added warmth. Stirrup Control System . Steel shank for stability.