Knee-high boots are boots that rise to the knee, or slightly thereunder. They are generally tighter around the leg shaft and ankle than at the top. Originally made of leather, versions made of a synthetic rubber (PVC, Neoprene, etc.), they are used by fishermen, dairy workers, stable hands, duck hunters, clammers, etc.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. Certain types can also be known as muckers or fishing boots.