Panasonic TH40 supports both 50 Hz and 60Hz (lever-switchable). A single unit can measure both the total time and a specific period of time. Compliant with CE marking standards. In a single hour meter, the upper display shows measurement specified-period and the lower display shows the accumulated measured time. A lever is used to select 50 Hz or 60 Hz. There is no need to rearrange the control panel and other signal destinations. Rotary indicator (Clockwise, one rotation per 2 minutes).