Castelli Nano Flex 3G Arm Warmer Belgian Blue, XL

Rain or shine, wet or dry, these warmers give you the extra bit of warmth you need to stay comfortable when you're riding on a brisk day in early fall or late spring. The stretchy, fleece-backed thermal fabric is coated with millions of tiny nanofilaments that encourage water to bead up and roll off the garment, keeping light rain and tire spray at bay. That being said, the material is also highly breathable, making them a great option for dry days, too.