Plugs are fasteners that can be used to seal pipes, holes or other openings. Plugs prevent the leakage of liquid, gas, dust or other substances and protect the inside of pipes from environmental influences. They are available in different materials, sizes and designs, depending on the application for which they are intended. They can be threaded, which screws into the internal thread of the pipe, or smooth-faced, which fits the external diameter of the pipe. The use of stopping plugs is a simple, quick and safe method of sealing pipes.