Membrane keyboards work on the principle of a flexible membrane that is located under the keys. When the user presses a key, the membrane touches the bottom perimeter, registering the keystroke. This type of keyboard is usually quiet in use, so it is suitable for office environments. Due to their design, membrane keyboards are also more resistant to dust and spills. The membrane underneath the keys provides a degree of protection against the ingress of foreign particles and liquids, which can help prevent damage.