The POL-FS5M2 Polar Bear Camera Cover is designed to keep the Sony PXW-FS5M2 warm in cold temperatures. It has a black nylon fabric exterior and is thickly padded and constructed of high-loft insulation. The interior is lined with a temperature-stabilizing, phase-change material (PCM) that helps keep warm air in the camera chamber. Air activated warmers can be placed inside the case to maintain interior temperatures in extreme cold temperatures (Portabrace Polar Covers have been tested at minus 50 degrees Fahrenheit).