All COD tests are available in a box of 25 tubes. Suitable for use in: Camlab Water colorimeters and photometers. Hach spectrophotometers and colorimeters. LaMotte spectrophotometer and colorimeter. Equivalent to: CW/24.20.720 for low range. CW/24.20.721 for medium range. CW/24.20.722 for high range.