The filter use starting date label for filter of the AP-C200 series products (FL-C200) was discontinued in January 2018 and the specification was changed to write the use starting date directly on the base unit of the filter.
There is a portion on the upper section of the filter with an inscription “Y/M/D”. Use a pen with an oil-based ink to enter the use start date.
Even if the filter use start date is not recorded on the filter itself, initializing the Filter Replacement indicator according to the procedures described in the instruction manual when the use of a new filter is started ensures that the Filter Replacement indicator turns on when the filter needs to be replaced to notify users of the replacement.
There are filters from some lots that are missing the “Y/M/D” inscriptions.