I would like to add a +2 magazine extension on my 870 Express with 18" barrel. I've found a deal on a couple different ones and am not sure if one is any better than the other.
Natchez has ATI for $36:
Sportsmans-Depot has ProMag for $27:
Cheaperthan dirt also has the ProMag for $27:
Cabela's has a Carlson's for $63:
Please advise or share your opinions on which would be the best one