These are my pair of Swedish pole climbers, got in the 70's from a telephone lineman. In Sweden they are called, directly translated to English, "pole shoes". The design is very clever, meaning the heavier you are, the tighter the grip on the pole. Just this pair is quite old and are made of cast iron; quite heavy as the pair weight approx 10 kilos (20 pounds) - gives you strong legs ;c) Modern ones are made of glassfibre thus very lightweight. I once lent these to James Bancroft so he could "copy" them...it's his pole shoes we used on our recent hunt in England and Scotland a week ago, pictures in the "Hunts and Finds" folder.