In addition to being very comfortable thanks to its left- and right-specific fit, Pearl Izumi's P.R.O. Barrier Arm Warmers protect you from the elements. Constructed from P.R.O. Thermal Fleece with Minerale for warmth, the P.R.O. Barrier panels protect your skin from the wind and shed water. Elastic grippers keep the warmers in place, and reflective highlights improve visibility.