2098-9636 Simplex Smoke alarm

I am trying to find a replacement for 2098-9636 Simplex Smoke detector that has operating voltage of 2.7 and alarm voltage of 6.7 printed on the label.

The closet match I found was 2.8 volt and 6.6 volt on Ebay. Do you think if it would work? How critical operating/alarm voltage range?

Please advise.

Any suggestion on the 2098-9636 Simplex Smoke detector operating/alarm voltage would be helpful. - Thanks.

It will work fine. They are the same model number.

These voltage indications have to do with the sensitivity testing boxes used at the time for these detectors. The test boxes had a test point output for connecting a voltmeter. The red dots represent the voltage levels at time of manufacture for comparison with field measurements. The voltage reading was used with chart to determine if the detector was in the correct sensitivity range or was out of range.