Hach Cod Vials found in: COD Reagent Vial Cooling Rack, COD Analysis Kits, COD Digest Vials High Range 20-1500mg/L, COD Digest Vial, Cod2 Lr, COD Digestion.. methods. Accommodates Most Test Vials The DRB 200 reactor can heat solutions in round vials of two different sizes. of two different sizes.