Perhaps the seller is referring to one like this:
http://www.villagephotos.com/pubimage.asp?id_=167855
I am very pleased to own this one! I call it my "poor man's Alembic" and it's pretty much all that. Maple body with zebrawood front and back, 5 piece neck through, 9v preamp, Gotoh tuners, heavy brass bridge, string thru, and very, very heavy. But you won't find another production bass around that has the harmonic overtones that this one has. I can play it unplugged (with new strings of course!) and hear 2 distinct harmonic tones above the primary note...and that's just fretting the damn thing!! Very bright but takes some twiddling to find the right tone. Very well made. You can see my review on Harmony Central. There were several wood choices available during the years of production. I've personally seen these:
Maple core/flame maple top
Maple core/koa top
Maple core/mahogany top
Mahogany core/maple top
Solid maple
Painted versions in black/red/and white
However, these basses are out of production so I doubt that the seller has a new one. Kawai also made another active bass - a bolt on neck - but they aren't near the style and construction of the F2-B's. You can see more about them on the Kawai
webpage.