The main uprights ( H pattern ) are 3". You can see 2" pipe buried in between some of the 3's that I use for connecting the H's for stability. It'll make a lot more sense once I get pictures of it together. It might be a bit obtrusive, but it works. I don't have any sleeves in the ground. Last year I just used the widest pieces of pallet wood cut to size to fit under the "foot" portion of the legs, to prevent them from sinking into the ground. I used augering stakes with rope for securing the whole structure in place.