Measuring just 39 mm x 39 mm x 20 mm, the new Mini Switch Monitor from Apollo Fire Detectors is a miniature interface with an entirely new housing ideal for installation in equipment with limited spaces. It can also be mounted within enclosures such as manual call points. The unit is designed to monitor the state of one or more single-pole, volt-free contacts and reports the contact status to Apollo-compatible control panels. It can also be fitted onto a standard 35 mm DIN-rail using a twist and click motion (patent applied for) and has a short-circuit isolator as standard. The monitor can be used as either an interrupt or non-interrupt device, the former meaning it can be used where a priority response is required in particular for monitoring either an individual or a zone of conventional manual call points. As well as normal, fault and alarm states, the unit also provides a pre-alarm state, allowing the investigation of a potential alarm so as to prevent false alarms from occurring.