Basic alarm unit for non-conductive and conductive liquids, monitoring and signalling of flooding caused by defects in pipes, basement drains or washing machines. With optical and acoustic alarm signal, integrated battery back-up for alarm, and log book (diary function) for reading out past operating states, connection option for remote signal generator (art. no. 20162) or can be retrofitted with potential-free contact (art. no. 80074). Including splash guard set for optical probe. Cable extendable up to 30 m.