Catherine - the brand name is Kahtoola and they cost about £45.
Available in any out door shop up here (Lakes) but also on internet I guess.
Hope you haven't missed the boat for this year - it was 14 deg today!

A seriously good bit of kit - they have rendered crampons virtually obsolete for most winter walking up here.

Tony - your micro- spikes sound good- where can i get some ?

Excuse me for being smug but my mate and I carried and used our micro spikes from Winter Hill onwards.
A seriously good decision which meant we were able to punch well above our weight! It was good fun to see all the fast runners using all their energy just to keep standing up never mind making forward progress.

Excellent account and pictures on Nick Ham's blog
http://ultraploddernick.blogspot.com/2012/02/anglezarke-amble-25mi-11022012.html
As well as the dislocated shoulder I was told of 2 fractured wrists and a broken arm - the only "walk" I have done where you didn't look for the footprints to determine the right route - you looked for the splashes of blood.

Felt good after completing 18 miles without breaking anything!.Huge thankyou to the Liverpool lads for not leaving me ! Thanks to the organisers who ferried us back - i'm sure they were kept very busy .I am thinking of re-doing when weather improves, perhaps early summer -any one want to join me ?