Eagle Creek Pack-It™ Specter Cube Set.  This is a set of 3 cubes.

Ultra lightweight packing organization. Three silnylon cubes that weigh less than 2.2 oz cumulatively, so that you can keep your clothing organized without worrying about weight. This translucent fabric is the same fabric used for lightweight tents and backpacks, it is super-durable, and stain and water-resistant.

http://shop.eaglecreek.com/packit-specter-cube-set/d/1229