I needed a liner that would let my toes breathe. Fall is coming and my boots are getting mud that is difficult to completely remove from the sole. they are light and comfortable. I wouldn't run many miles in them as they don't have as much cushioning and aren't stiff on the outside. But they stay clean on the inside, let your feet breathe and don't overheat. They don't slip on bamboo floors or concrete, and there's hardly any heel wear when putting them on and off. The elastic band on the front sides makes it easier to slip on and doesn't knock my socks over. We'll see how long they last, so far so good.