HI839800 COD Test Tube Heater. NZ $1356.00 + GST. Product Code: HA-HI839800-02. View Product +. HI93754A-25 COD Low Range Reagent Vials, EPA Method (25 tests) NZ $97.50 + GST. Product Code: HA-HI93754A-25. View Product +. HI93754B-25 COD Medium Range Reagent Vials