Use this clear, redesigned, 60-cm tube to accurately measure the turbidity of shallow or flowing bodies of water where a Secchi disk can't be used. A single operator controls the water-level discharge from the tube by gently pushing it against the ground to activate the stop plunger when the 45-mm Secchi-disk design is visible. This action immediately stops the flow of water to accurately and efficiently measure the water's transparency. This unique tube features a side scale with centimeter and Nephelometric Turbidity Unit (NTU) markings (0 to 60 NTU scale).