It's essentially a bass ukulele shaped like a NR TBird. Amazon sells them...
https://www.amazon.com/Savannah-STB-700-VS-Lightning-Bass-Guitar/dp/B016KMRMNY
I have a hollow body Kala bass uke and Chucky is right, the bottom end is earth shaking massive. Unfortunately, because of the piezo in the bridge it also has a fairly bright top end. I use mine with a small combo amp and have to EQ it with the treb knob completely off and the bass knob nearly off. The strings are a type of rubber (I like the black ones not the white ones) so it takes some getting used to, but once you get the hang of it they can be a really fun and rewarding bass to play. EQ is critical, these little buggars will walk all over the rest of the band and completely bury a heavy hitting drummer or loud keyboard. I about gave a sound guy a heart attack during set up when I plugged it into my normally EQ'd SVT-VR and 610 rig and hit one note.
Warning, you'll look goofy on stage, like most Uke players do, but for a fun take on the right song it can be a big hit with the audience. I used to play my Kala for the Offspring song Pretty Fly for a White Guy, it was the perfect look for that song. More of a novelty bass than a workhorse.