The YSI 6155 optical DO membrane kit is a replacement kit for the 6150 ROX optical dissolved oxygen sensor.

Note:  All optical DO membranes are now manufactured from anti-fouling copper alloy; these membranes directly replace black plastic membranes. Anti-fouling membranes can be used on existing ROX probes with no detrimental effects on data. The copper-alloy YSI 6155 optical DO membrane may arrive with surface patina and/or discoloration. This will not affect membrane performance.