Good question. I notice that there's a removable section on the back. My guess is you pull that off, then thread the strings through the bridge (kind of like electric through-the-body designs). If so, that's an interesting variation on the pinless bridge. I think I'd like that. I own a few electric basses (though I really don't play bass much). I pretty much never change the strings on them (since I'm not into slapping, I don't really care if I lose the highs and I have yet to break a bass string). Without bridge pins, it's a nice, clean design.

Yes Brian has it spot on.

Simply screw off the back plate and feed them through. If you have a small arm you can even do it through the soundhole but thats a bit tricky.

I always hated the bulky look of Bass pins so this is a neat solution.

Alistair