water hammer arrestor

[bbxrider]

my bath remodel, moved toilet, replumbed copper from 1 sink vanity to 2 sink and replumbed copper in shower to add a second valve and its faucett.
now before I close it all up, wondering if I should put in the water hammer arrestors? I have never had any hammering up till now, so its not imperative but checking on opinions from folks with past experience.
looks like I would need 4 arrestors for the shower valves and then 2 more for the h+c for the vanity and toilet. those arrestors would be pretty far from the valves for those fixtures.
any experience with specific arrestors? or are all pretty much the same for this type of installation?
many years ago I plumbed a bath remodel and back then we just plumbed in some 1/2' pipe coming off a tee to an elbow with about a 10" riser coming off the elbow with a cap. there was both h+c about 10" from the combo tub shower valve. can't remember if there were the arrestors like today.

 

[phishfood]

When in doubt, add water hammer arrestors.

 

[bbxrider]

ok thanks for the input

 

[frodo]

we call those air chambers. we use a 3/4'' pipe 12'' long.

they work ok, only draw back, is you need to shut off the water and drain the system 1 x a year or they get water logged

 

[bbxrider]

ok interesting, so save some $, but to have to drain system even 1x per year, not for me, would pay for the 'official' arrestors and not have a another chore,