Product review (5 stars): easy to install and fixed the water hammer sound problem i had
What more can I say? I took no more than 15 minutes for me to install this inline to my dishwasher water line.

Afterwards, no more clunking water hammer sound. I was amazed!

This version works specifically for the diameter water line it was specified for (3/8"). Inside the unit, which you cannot open up, is a pressurized disc in the long chamber. What this does is when your appliance quickly shuts off, the reverberating water pressure is sent into the arrestor. It pushes up against the disc, acting very much like a shock absorber. Because it functions this way, it prevents your water pipes from bearing the brunt of the pressure and knocking inside the walls.

By the way, having water hammer occurring is not a good thing: it will eventually loosen the pipe fittings and may cause a very expensive leak within your walls that you'll have to tear it down to get at.

I would highly recommend this product. Sioux Chief makes other size water hammer arrestors for other purposes too (like for toilets, washing machines, etc.) They make an arrestor to fit just about any water line you have.