These are replacement liners for Hoffman Pac Boots, (10" High). Hoffman's highly recommends rotating your liners for moisture control and to extend the life of your boots. Note: replacemant liners will only fit in boots designed for felt liners. Specify size when ordering by phone or select size in the drop down window if you are ordering by phone. Here's a tip...........order an extra set of liners when you purchase a set of pac boots and the liners will be shipped free along with the boots.