9"/15" Long 100/200 Micron Rating Fish Aquarium Ring Nylon Filter Sock Q111-114 Perfect for using on your return pipe in your sump tank Filter sock is made from high quality nylon, and can be cleaned and reused many times Ring width: 4 Inches Length: 9"(short) and 15"(long) for your choice Micron rating: 100 micron (0.1mm) and 200 micron (0.2mm) for your choice