It's very similar to the VT200 except it's pretty damn small and it only has two inputs and one output. Though that is pretty much all we use on our cars anyway.
It has built-in antennas and is waterproof the same as the VT200.
I've got a couple of these for testing at the moment and if it all checks out, I'll bring a batch in.
My supplier is also no longer selling the VT900 except for orders of 750+ and that's definitely not happening. So the VT200 and VT100 will be the models for now. The VT100 should end up slightly cheaper than the VT200.