Allstar Black 5 inch x 9-3/4 inch Single Hole Offset Plastic Brake Cooling Duct features a cooling duct that has a single hole that is centered. The measurements are 5-1/2 inches x 9-3/4 inches with a 3 inches o.d. inlet. It is constructed from heavy-duty black plastic. The brake ducts are designed to direct outside air to brakes, oil coolers and the driver..