Here's what the website said about it:
The Parka is the same design as the Mountain Jacket, but with a fixed hood and thicker pile. Ideal for polar exploration*, indeed it was first made for use in Antarctica with the British Antarctic Survey. It is too warm for most activities in normal UK Winter conditions. Best suited for inactive use where body heat is not being produced by any exercise. 1190g.
WARNING: Buffalo is NOT waterproof!
*Polar exploration? Do walkarounds in MEM count?