ABN Filter Sock &ndash; 200 Micron PP with Plastic Ring 4&rdquo; x 13&rdquo; Inch &ndash; For Fish Tank, Aquarium, Refugium, Sump Pump Practical: The ABN Sock Filter  200 Micron PP with Plastic Ring 4 x 13 Inch  For Fish Tank, Aquarium, Refugium, Sump Pump does the hard work for you and keeps your aquarium water crystal clear so your fish stay happy and healthy Versatile: 4" x 14" (10cm x 35.6cm) felt sock filter with a 4" diameter plastic ring that fits in most sump and refugium holders for easy suspension and all filtration needs; Use for a circular bracket holder, attach to a line or catch with the plastic loop inside the ring; Reduces micro bubbles and filters out fine sand and other gunk before it goes further downstream and plugs the smaller filter media Improves Water Quality: Interlocking micro-denier felt fibers designed for trapping uneaten food, waste, decay, dust, and other particulates but allows water to flow through; Changing regularly increases water quality by removing organic compounds before they break down and create added nutrients such as algae Durable: Polypropylene (PP) 200-micron non-woven synthetic felt fiber filter effectively traps small dirt particles and does not clog as quickly as smaller micron filters; Heavy-duty stitching; Can be cleaned and reused numerous times; Last longer than polyester sock filters Washable: Reusable; Just turn the filter inside out and throw in the washing machine with hot water and no detergent soap; Bleach is safe to use on this filter