To make the Therminal Engineered Arm Warmers we used a special cylindrical knitting machine that allows us to engineer areas of stretch compression and articulation while also creating a seamless design Lighter weight than our standard Therminal Warmer collection this seamless version is perfect to stash in a jersey pocket when you need a little extra protection on a fast descent or for a long climb in the shadows We use a yarn that offers good loft for trapping body heat and adding a good sense of durability while a knit construction allows for excellent air permeability and breathability This technique and design also comes with the added benefit of aligning with your elbow joint so the warmers will stay put with just the right amount of compression at the arm and wrist cuffs