Visibility Disc acc. to Secchi, 3m steel rope, ma Back Catalog number: 443590 Manufacturer: HYDRO-BIOS Availability: In the manufacturer's stock Price on request - + Recommended 438150 Plastic Net Bucket with snap-in bolt Price on request 438110 Mechanical Flow Meter Price on request 450536 Oxygen Sensor OxyGuard Ocean D.O. Probe Price on request