The wheel-size is 20" for all giraffes and so the floor to axle distance is always the same. The measures (1400, 1500, ..., 2500) are the distance from the floor to the seat in mm for a 1.80 m tall person. The giraffe can come with a shorter seatpost or the seatpost for the model TRAVEL can be shortened.
Pichler unicycles and giraffes are very common here in Austria. I use a Pichler Solo unicycle as a muni and am very happy with it. I have been riding the TRAVEL 1500 a few times, I liked it.
...The wheel-size is 20" for all giraffes and so the floor to axle distance is always the same. ...
Hans *
You could have your Pichler giraffe with a 24" wheel as well. That's actually what I had at home at some time. The 24" wheel is nice when you would like to go on a longer trip with it.
If you have more questions, you can also try to ask Mr. Pichler himself by email (address is info at pichlerrad.de); I'm sure he will answer you in english.
Juergen (happy pichler customer, no giraffe, though)