Is the SIN300 C-band rectangular grating coupler period incorrect?

[inwwin]

cspdk/cspdk/sin300/cells.py

Line 304 in 22631bf

period: float = 0.66,

According to the Cornerstore's publicly available MPW11 PDK document, the period is 1320nm, but here it is 660nm which is exactly half of the published number.

Is this intentional or merely a mistake?