A sprained ankle on the trail or a weak knee in sports needs a really firm bandage that won't move in strenuous activity. That's what a self-grip bandage does. I've been amazed at how firm a purchase this tape can make against itself. It holds itself together much tighter than a velcro grip (and far better than any Ace bandage), yet is quite smooth against your skin (it only sticks to itself). In fact it is so steadfast that unwrapping can be a challenge. It even adheres (to itself) under water. Comes in colors, too.