My concert Flea has a saddle/bridge that is all one single piece of molded plastic (or fiberglass?).
My tenor Fluke has a wooden bridge, with an actual slot, that contains a saddle, that appears to be removable.
The photos on their web site show both kinds on various instruments, depending upon which one you look at.
Curious about this, back in January, I called the Magic Fluke Company and spoke to Betsy, and she told me that when you order one, if you have a preference you should indicate it, otherwise they will use whichever is on hand at the time when your instrument is assembled. I forgot to ask if you can send them your instrument and have them replace one kind with another. (which would require removing the fretboard and the top)
Why? (sorry if the next part is slightly off-topic)
If you want to install an under-saddle transducer pickup, post-purchase, or if you got your Flea/Fluke used and it did not have a pickup installed at the factory, you can NOT do this yourself or with a local luthier with the all-one-piece molded saddle/bridge, but if you have the 2-piece saddle/bridge, then there should be no issues, provided that you take care not to drill through the rivets that hold the bridge on when you make your holes for the ribbon wire of the under-saddle transducer pickup.
For both ukes, my fingers are about an inch too short to reach deep enough inside to the bridge plate from the sound hole in order to attach a surface transducer pickup right in the sweet spot. I know you can put one forward of the bridge plate, and I've done this, but it picks up a tremendous amount of surface and body noise.