Ulfhednar has a number of support bags/pillows for different uses. All made with only the most durable materials. The "Brick" is a sqarish rear support pillow where no side is alike in height. Filled with SpexLite plastic pellets. The filling may be adjusted using the YKK(R)-zipper opening. The Brick also features Top-Grip friction material on one side. FeaturesDimensions: 4.92" x 3.94" x 2.95"