In reply to Frank Mitchell:
I used one last winter in the Cairngorms - kept me snug in a howling, snow-laden, icy blast. Generous hood was fine over an ecrin helmet. Generous fit chosen to go over my Helly Hanson pile fabric jacket and Montane wind-proof smock (can't remember the name). All worked well.
Can't wait for the coming snows....
(I got mine for £50, at Cotswolds - ace value)