eBags Ultralight Packing Cube - Large (Blue) 30D siliconized Cordura brand nylon for the optimum combination of durability and light weight Silicon coating on the interior surface makes it easy to fill. Polyurethane coating on the exterior surface reduces shifting of cubes inside your luggage Patent-pending spring-loaded mini framed design helps the cube hold its shape while filling Premium self-repairing coil zipper with color-matched corded zipper pullers Hypalon tug-tabs give you something to grip when closing the zipper