This is a replacement pulse output sending unit for EKM water meters.

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Sizes: 3/4", 1.0", 1.5", 2.0"

Type: Pulse Output Reed Switch

If your water meter's pulse output has stopped functioning, you can replace it instead of replacing the whole water meter. The replacement process requires a bit of DIY capability as there is no instruction manual. 

To confirm that the pulse output of your water meter is not working, you can do a continuity test on the pulse wires with the water flowing. That test is explained in this video: https://www.youtube.com/watch?v=l8oYAUmuBD8