Look for reviews for the Korkers Tundrajack. The 600 Polar Vortex are a new version of the Korkers Icejack (600g) and the 1200 Polar Vortex are the new version of the Korkers Tundrajack (1200g). I have had a pair of the Icejack 600g for years and love them. They're light, have held up great and you can't ask for a more versatile boot with the interchangable soles. Hands down the absolute best boot I've ever owned. The 600g is plenty warm enough fishing in the shanty or moving around and too warm to say run errands in for an afternoon...like store to store. I wouldn't want the 1200g unless I was fishing out in the elements on the ice with no shanty.