https://github.com/demberto/PyFLP/blob/816c78dadddcb6eeb391bf318fda4ff1b9fcfb88/pyflp/arrangement.py#L131 https://github.com/demberto/PyFLP/blob/816c78dadddcb6eeb391bf318fda4ff1b9fcfb88/pyflp/arrangement.py#L512-L513 Its actually the height of the `ChannelRack`. 
PyFLP/pyflp/arrangement.py
Line 131 in 816c78d
PyFLP/pyflp/arrangement.py
Lines 512 to 513 in 816c78d
Its actually the height of the
ChannelRack.