My life has never been the same since discovering packing cubes. I initially used them only for travel, but now I use them for all kinds of things around the house. I even use them to organize my clothing drawers. This particular one, however, is one of the best I've seen and it's perfect, particularly for travel. It has a compression zipper that works kind of like expandable luggage. If you keep it zipped, there's a small amount of storage space, but if you unzip it, you suddenly have many more inches of depth to the cube. Additionally, there's a zipper on the top and a zipper on the bottom of the cube, with I separator in the middle, essentially combining two cubes into one. This is where the brilliance of this cube comes into play. One side is breathable like most packing cubes. The other side has a waterproof lining. This is the perfect way to be able to store dirty clothing without contaminating the rest of your clothing. It's brilliant. You pull the clean clothing out of one side, wear it for the day, and at the end of the day, put the now dirty clothing on the opposite side of the packing cube in the waterproof section. You could also put wet items in there and not worry about other items in your suitcase becoming wet. This style of packing cube is a traveler's dream. I look forward to ordering more in different sizes. FYI, it is soft sided. The images make it look like it might have a hard exterior, but it does not.