429 Stainless Steel Point Source Bailers have an easy sample release device and dual check valves top and bottom. The check valves prevent water at other depths from mixing with the sample during retrieval. Point Source Bailers are available in 0.5", 1", 1.5" and 2" diameters (12.7, 25.4, 38.1, 50.8 mm), and lengths from 2 ft to 4 ft (610 mm and 1220 mm). The 103 Tag Line with marked cable and Power Winder can be used to facilitate the raising and lowering of the bailer.