It depends on the gun you shoot. I would go to a "GUN STORE" and have an expert help you out. Cabela's is cheap. and so is their advice, but their advice is usually worth exactly what you paid for it. Briley makes excellent choke tubes for steel shot for most guns and they have a chart that reccommends which tube to buy for whichever situation you are hunting in, whether it it pass shooting or close decoying etc. The advantage of extanded tubes is you don't need a tool to tighten or loosen them and some are ported to tighten up the pattern by slowing the shot cup down a fraction of a second behind the pellets. There are others out there that know much more about this than I do. I just bought and shoot what they tell me to.