Citizen OP900II Technical Manual page 41

(3) Ribbon Status
To display the current ribbon status, click on "Get".
(4) Print Sheets Counter
To display the Life counter, Counter A/B, and Matte Counter, Counter M, click on "Get".
To clear the Counter A/B, click on "Clear A" or "Clear B".
To clear the Counter M, click on "Clear M".
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