Looking for some education on this AR part

[Armed Eye Doc]

My buddy bought a gun shop and this pigtail gas tube was in the shop.  

I can tell that it goes on a pistol length gas system and extends the length of travel of the gas.  But I don't know why. 

I don't have any AR pistols so have no experience.  So, I thought I would ask here if it is something worthwhile and has a true purpose.  Or if it is complicated shiit that will complicate shiit.

[jim3326]

That is interesting. My best guess would be to reduce the kick, but I would think an adjustable block would do the same. Beats my 2 pair!

[shooterrex]

That was designed for the pistols to make the gas tube carbine length. That should slow down unlock etc. 

Not sure it actually worked but that's the story.

[98Z5V]

1 hour ago, shooterrex said:

That was designed for the pistols to make the gas tube carbine length. That should slow down unlock etc. 

This is exactly right.  Rex nailed it.  Softens the felt recoil impulse of a short gas system, and slows down the unlock time of the bolt from the barrel extension. 

[Armed Eye Doc]

I knew I could get a  reliable answer here.  Thanks guys!