If it has two large baskets it's the 2210 (old style with the push together baskets) or the 130/2402 (new style with the baskets that clip together). It doesn't matter if it's an old style or new one, they are both for 60 to 160 litres tanks (their figures) with an output of 180 to 550 litres per hour. Whether you take the large baskets off or not, it would probably be too powerful for a 26 litre tank, even with the flow turned right down, unless you modify it with some sponge over the outflow.
I have the smallest aquaball, the 2006, for my 25 litre QT. It comes with a small sponge and no large baskets, and is for tanks up to 45 litres, 100 to 380 l/h. I've added a large basket with large sponge to it, but the flow is still so strong I've had to tie some net over the outflow.
Try yours by all means, but you may find you need to do some serious modification to it to stop the fish being plastered to the opposite side of the tank.
