they are exactly 99cms, which is 39 inches (or 3.25 feet).
as you can see they are twin-tipped so they are for stunting more than speed (since they are so short, they tend to wobble at higher speeds). The carving ratio is also VERY short, some 8 meters. Nowadays they use these things to teach the proper carving technique, before moving to longer skis.
They are AMAZINGLY fun to ski with, you can do whatever, ski backwards, jump, go a little fast, carve... you name it
Only caveat is braking, since there is not much surface, braking takes a bit longer