Valley Electronics Daysy Instructions For Use Manual page 14

Clean Daysy with a damp cloth when needed. Avoid using too much water,
as Daysy is not waterproof. Alcohol and soap can be used in small amounts
if necessary.
The battery lasts approximately 2 years. If the battery is nearly empty,
Daysy's activation ring will blink frantically. If you change the battery
within a day or two, your fertility calculations will not be affected. If the
battery depletes completely, Daysy will have to relearn where you are
in your current cycle.
Note: When changing Daysy's battery, be sure she is "OFF" before removing/replacing her battery.
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