Them are Daves Mud Shovels - front and rear. Made by Portland Design Works (PDW). Designed by Dave Gray from Surly who was one of the main guru's behind the Pugsley. Fat bike specific, fantastic, I highly recommend them. Very light weight, really easy to install and take on and off as conditions dictate. I've had the pleasure of meeting and throwing a few back with Dave. He knows fat.

Here's some links - and a side shot

http://surlybikes.com/blog/post/some...s_for_a_change

http://www.ridepdw.com/goods/fenders