Completely and utterly possum pelt, with a domed front that can come down over the forehead, and flaps that dome around the back until you need to stop the wind and cold on your neck. Utterly exquisite feeling: incredibly warm, incredibly light. Often seen in Antarctica (hence the name). Also seen these days mucking out horses, deer-stalking and flying along in open top sports cars around Edinburgh!
Sizing is based on head circumference:
Medium: 57-59 cm
Large: 60-62 cm
Extra large: 62+ cm
A more snug fit is advisable.

"Hi, just to let you know that I have just come back from Finnish Lapland. My possum socks, possum insoles and 30 Below hat kept me lovely and warm. The temperature ranged from -17 to -33 and I never felt the cold at all. Warm head, warm feet - thank you very much! All the best, kind regards,
GS, Gloucestershire"