PRODUCT DESCRIPTION This flat edged brass roller is affixed to a nylon constructed housing. The brass rollers have a diameter of 3/8 In. and install 2 per window. Fits Elco-Century, Better-Bilt, and Viking windows. FROM THE MANUFACTURER This flat edged brass roller is affixed to a nylon constructed housing. The brass rollers have a diameter of 3/8 In. and install 2 per window. Fits Elco-Century, Better-Bilt, and Viking windows.