Here is what I can get in my Topeak Micro 1/2 liter bag with a little bit of room left. The tube in the bag is 32mm.

I just recently considered getting a Scicon but they didn't have a size in this range I liked and for the smaller size Scicon but the connector seemed as big as the bag! The Topeak connector is quite light and has been completely reliable for me for many years riding over rough roads and trails.