Knee-high boots are boots that rise to the knee, or slightly thereuner. They are generally tighter around the leg shaft and ankle than at the top. Mostly made of a synthetic rubber (PVC, Neoprene, etc.), they are used by fishermen, dairy workers, stable hands, duck hunters, clammers, etc. to protect the feet from water, mud, manure, etc. and to provide traction on slippery surfaces. Most slip on, but there are varieties with buckles and those that lace up.