I made these biiiig and then stuck them in the washing machine to felt: result = fantastically warm and almost windproof mittens. The 2 thumbs is an old iceladnic way of doing it for fishermen: 1. if they tore you could turn them around and keep using them. 2. the inside would felt more with use, so you could turn them and felt them evenly, having a warmer side on the back of your hand. Today I use them for riding: they are big but you can feel the reigns and never get cold hands, not even when the wool is wet. The best ever!!!