- Two or more highly conductive reeds inside a glass container. The reeds open or close together in response to a magnetic field.
- A switch whose contacts are mounted on magnetic reeds, and which is hermetically sealed in a glass tube. Such a switch is designed to be actuated by an external magnetic field. The contacts are not wetted by a pool of mercury, as is the case with a mercury-wetted reed switch. Also called dry-reed switch, or magnetic reed switch.