BUWUSMU 7.87 Inch Plastic Secchi Disk Set - Secchi Disc with Black and White Quadrants, Steel Cone, Holding Line, and 30 Meter Tape Measure for Clarity Measurements

Good quality but the tape does not start at zero - there is an additional 16 cm of tape which creates a measurement error.

Measurements are metric only

When I ordered this primarily for the 100 foot tape. Unfortunately, when I received it, it only reads in meters and not feet. I'm afraid I won't get much use out of it from that standpoint As far as the disk and being able to measure the depth and clarity of the water, it works just fine. I tried it in a fairly clear lake I fish and was able to see it to about 9 feet. It's a large and easy to see disk and has the proper weight on the backside of it, so you can lower it into the water easily.