Available in standard shoe sizes from seven to 13. Shell and lining are waterproof 200-denier oxford nylon. Insulation is Lamilite. the core of the sole 3/8 inch close cell foam. Will fit any brand of pack boot. You will wear out your pack boot before you wear out the sun walkers. In addition they can be used as booties. You will never again be concerned about wet pack boot liners.