16oz = 1lb.

Yes, the 32oz model is 2lbs. I got this model because I figured with my 5.5"+ flaccid length I would be ok.
It's about 2.25" long (just measured it). I'd say, if your flaccid length (stretched non bp) is shorter than 3" you should go with a smaller Circle Device. I picked the 2lb model because I wanted the best results in the shortest time. Not only that, but I have plenty of past experience with weights to figure that 2lbs would not be overkill. I'd suggest if a guy were to buy one that most men would be fine with the 2lb model. You may have to work up on the amount of time you can wear it however.