The original Jackal impressed ultra-runners with superior cushioning and stability suitable for long miles over rough technical trails. La Sportiva not only added reliable waterproofing to the Women's Jackal GTX Trail Running Shoe but also made sure the waterproofing didn't interfere with the shoe's ultra-worthy performance. Gore-Tex Invisible Fit is a newer type of waterproofing from Gore-Tex. It's the thinnest lightest membrane that Gore-Tex currently makes and while it's still dependably waterproof when you're running in the rain it's also remarkably flexible and breathable once you're back in the sun.