weight of shower heads

[namsilat]

I am considering installing dual/double shower heads, but I am concerned about the combined weight of the setup putting stress on the shower arm, especially in the long run. Is there a safety number of some sort in weight that I should not exceed to avoid risk damaging the arm?

 

[Geofd]

If the piping behind the wall is supported it should be in k to hold a reasonable amount
Of weight how much do they weigh together?????

 

[namsilat]

Yes the shower arm come out of the wall. I have no idea exactly the weight yet, just checking out items online first. I am seeing in description some of them may be 800-900g, that sounds heavy (2 lbs) especially it's going be years of it hanging on the arm, hence my concern.
How far off the wall would it be it would have to be supported from above if to far with stainless hardware