When selecting a switch for an application, it is often necessary to have some degree of protective sealing to protect the switch and circuitry from the environment it will be used in. Sealed switches have a specification called the Ingress Protection number, or IP number. As can be seen on this slide the IP number is a combination of protection against dust, from no dust to dust tight, and protection against water, from no water to continuous immersion. In addition, C&K switches are process sealed for convection reflow solder process and aqueous cleaning.