The Swiftwick Aspire Four Socks are created by a 200 needle machine process that yields a high density, seamless knit fabric. The process allows variability in the finished knit of the socks, as different parts meet different performance requirements. For example, the cushioned footbed gives way to the thin channeled upper both components playing a crucial role to increase your comfort. When you slip into a pair of Aspire Socks, you'll immediately feel that they're tailored for your feet. The arch band offers snug support in the midfoot, and the Y shaped heel contour assures no bunching or overstretched feeling in the back. The four in the name refers to the four inch cuff height. This height makes them feel great in inclement weather when a bit more coverage may keep grit and dirt from falling down into your socks as it gets thrown up from the front wheel. In addition, the taller cuff height, along with the multiple knitting patterns in the footbed and cuff, adds to the compression nature of the socks to promote blood flow in the feet and lower legs. And as you might guess, improved vascular performance means reduced fatigue and speedier recovery. The dense nature of the material all but guarantees durability when combined with the abrasion resistant properties of Olefin, one of the prime components of the foot of the sock. Olefin is a lightweight polypropylene fiber that Swiftwick sources from US manufacturers. Then the socks are created in Tennessee in Swiftwick's own factory, where they can oversee every step of the process to ensure tight quality control. The Olefin wicks like crazy to keep your feet dry, but removing moisture from your skin is only half the story. Olefin is also hydrophobic and will not absorb water, so the moisture transfer is complete all the way to the outside of the sock. You'll stay dry, comfortable, and blister free since the socks move with your feet and minimize or eliminate abrasion against your skin. The Swiftwick Aspire Fo...