Running-time hour counter for Katadyn ultraviolet disinfection systems, 230 V 60 Hz supply, non-resettable. It records elapsed UV lamp running time so lamp changes can be scheduled on hours run rather than calendar age. The non-resettable form cannot be zeroed, giving a permanent cumulative record of the plant's service. Check the supply frequency against the installation: the 50 Hz counter is a separate part. Reference number 1151-0706.