When you buy the medial bell detectors & alarms pro, what you are really buying is predictability. At a glance Type: Medial Bell Power: AA Battery Sensor: Semiconductor Compliance: CE Price: à§³19.73 (offer à§³17.12) The part most missed Set up as a medial bell-class unit, it does the job without asking you to improvise. In practice First use: no break-in ritual required beyond a quick wipe and a glance at the label. Care: a rinse and dry cycle in the usual rhythm keeps it looking fresh. Storage: stows neatly, taking no more room than a loaf tin when out of service. A solid, predictable choice for anyone who would rather not think about the item again.