I've used these to prune much larger branches than I think they're probably intended for.  It's difficult to say what the maximum thickness branches they are intended for because the documentation on the package gives no such guidance.  Nonetheless, they are holding up very well even when I should probably look for my loppers but when I'm too lazy to do that, "just for this one branch."  I just use a sort of twisting, "sawing" motion to get the branch down to size a bit before I execute the actual cut.  The blades are easy to lock closed with one hand so you can stick them in your pocket and not get stabbed after you forget they're in your pocket.  Keep the blades sharp and clean the blades with a wet rag, then with a dry rag, and finally wipe with an oily rag after each use and I think you will be glad to have these for a very long time!