Sight glass according to Secchi

Viewing window according to Secchi, WINLAB® For determining the visual depth and light transmission of the water. This new solid made of strong plastic and is additionally equipped with a sinker for better with a sinker for better lowering. The approx. 15 cm high bar is equipped with an eyelet for the sinker. Viewing window With eyelet without plumb line 250 mm Ø more