Replaceable Thermal Boot Liners Replaceable boot liner for the Ice Diamond ID503, manufactured to the very highest standards. These Sherpa fleece liners offer cost effective maintenance and longevity for your Ice Diamond boot. The wearer's feet are kept warm and dry at all times because sweat is removed to the exterior of the liner fabric. Alongside these advanced wicking properties, the fleece lining keeps feet warm by trapping more air, while special gripping material ensures the liner doesn't slip inside the boot.