Liquid level sensors utilise reed switches in a stem that are activated by a magnet in a float. With a large range of different plastic materials for stem and float, these are suitable for use in many fluids, including corrosive acids, and can often be used at temperatures of 120°C. Other options include vertical or horizontal mount, assorted fitting methods and external or internal mounting. A further range of sensors in a basic metal design completes the range and features APEX approved parts.