Hanna buffers are specially formulated to have an expiration of 5 years from manufacture for an unopened bottle

reverse osmosis (RO) system verification

Automated Nutrient Control: Maintains precise EC/TDS levels without manual intervention

Test Parameters: Free Chlorine + Total Chlorine

⚠️ Never store in distilled (DI) or Reverse Osmosis (RO) water — this damages probe sensitivity

Milwaukee MA841 Dissolved Oxygen Membrane Kit - 5-Pack for MA840 Probe Seychelle Hanna buffers are specially formulatedReplacement Dissolved Oxygen Membranes for MA840 Polarographic Probe The Milwaukee MA841 is a professional grade replacement membrane kit designed for the MA840 Polarographic Dissolved Oxygen Probe used with the MW600, SMS600, and Mi605 Dissolved Oxygen Meters. This 5 pack ensures you have spare membranes on hand for routine maintenance and optimal DO measurement accuracy. Key Features: PTFE Membrane Technology: Oxygen permeable