I can't tell you the measurements, because my eyesight isn't really good enough for that, but I can confirm that the lower lift portion (part 30 25 4343), when attached to the outside of the baseplate, is the same height as the tall walls and wall connectors:

And the upper lift portion (part 30 25 4353), again when attached to the outside of the baseplate, is the same height as the smaller walls and wall connectors:

One wouldn't normally put it together like in this following photo, with a gap next to the lift, of course - this is just to demonstrate the heights:

Note that the upper part is the top (and ending) of the lift. If you wish to use this lift on more than two levels, you would need extra lower parts 30 25 4343, and have taller walls on every level except the top level.