Can you ID this ?

[Mike Picarello]

Is this a pressure reducing valve?
It's on the water main.

[Billy Stephens]

Is this a pressure reducing valve?
It's on the water main.
.
Yes ( or a docked UFO ! ) :D
.

[John Arnold]

Looks like a water hammer arrestor to me.

[John Arnold]

Watts Series 150A Water Hammer Arrestor 1/2" (0269503) at Remodelr.com (http://www.remodelr.com/Prod/Watts-Series-150A-Water-Hammer-Arrestor-1-2-0269503/RM6287/Cat/240?gclid=CJ_Mit3286wCFQPe4AodyQrLTw)

[Billy Stephens]

Looks like a water hammer arrestor to me.
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And We Have A Winner.
.

[Mike Picarello]

Thanks fellas

[John Arnold]

Thank you. Thank you very much.

[Corn Walker]

All of that corrosion makes me wonder if that's actually a brass MPT adaptor or if it might actually be steel.