Gassing Cover for Honeywell Optima Plus, in lieu of calibration cup.
We advise using the Optima Plus Gassing Cover (2108D0258) because it fits over the storm baffle on the Optima Pus. If they select the calibration cup (2108B0272), you will need to loosen the plastic lugs and remove the storm baffle on each Optima Plus to perform a calibration.