This thing works amazingly well. Previously I had no end of trouble with sweat dripping into my eyes and all over my glasses. I tend to sweat a lot and thought there was nothing to do about it but stop and try to wring out my helmet liner every so often. I didn't like the idea of a headband or do rag because I thought it would make me hotter (and I already run hot) but this doesn't -- not even on a scorching day. It simply absorbs all the sweat from under my helmet and prevents any of it from dripping down, and seems to actually keep me cooler. Even in a tough, hot 20-mile race with 3,500 foot elevation gain in 82 degree heat last weekend, not a drop went in my eyes.