I think it's a TacStar I have on my house 1100. Two shot extension. Works fine but it's not like I'm shooting a flat through it on weekends at clays or anything.

There's not a heck of a lot going on with these devices. If the tube is straight, and the threads screw down tight, there's not much else to say about that part. The spring is probably the most important part of the setup. Whatever follower you are using is likely more important than the extension itself.