Product review (4 stars): Effective, easy to install, but probably not lasting forever
My main bathroom shower used to make terrible hammering noice when I turned on the water at some point from cold to warm. I installed two mini-resters under the sink, one in the cold water line, the other in the hot water line, and the hammering noice disappeared! The installation was easy. You will need two flexible pipes from Home Depot or Lowe's to replace the rigid copper pipes under the sink in order to make room for the arresters.
I did this 3-4 years ago, and the noice recently came back. So I bought two more through Amazon, a few dollars cheaper than I could get locally, and replaced the older ones. The noice again disappeared! Obviously, this device has a limited life span. I think I can live with that, to replace the arresters every 3-4 years.
But what should I do with the old ones? I don't feel like throwing them away in the trash, because I think they can be easily fixed by replacing the valve inside. I hope there is a recycle program for this.