Aquatic Experts Filter Socks 200 Micron - 4 Inch Ring by 8 Inch Long - Short - Aquarium Felt Filter Bags - Custom Made in The USA for CUSTOMER AND PROFESSIONALS CHOICE - Our 200 micron filter socks are BEST SELLERS - the TOP CHOICE for my clients as well as my aquarium service technicians and both chose 200 micron socks because they do not clog as quickly as smaller microns do, yet they help ensure crystal clear water. HIGH QUALITY AND REUSEABLE - Solid construction and heavy duty stitching make these socks STRONG AND DURABLE so they CAN BE CLEANED AND REUSED NUMEROUS TIMES. You will receive four 4 inch by 8 Inch felt filter socks with a 4-inch diameter plastic ring that will fit most sump holders. THESE DO NOT FIT RED SEA FILTERS. CUSTOM MADE: Our filter socks are constructed only when our factory receives our exact specifications; years of testing produced the perfect blueprint. Other socks may look like ours but if you want the best you have found them. To see all of our sizes and quantities simply click above on - by Aquatic Experts - under the title. IMPROVE WATER QUALITY- Our filter socks have interlocking micro-denier felt fibers that are perfect for trapping uneaten food, waste excreted by livestock, decaying plants, detritus, dust, and other floating particulates. Changing filter socks regularly will INCREASE WATER QUALITY by removing solid organic compounds before they continue to break down and add additional nutrients (which can increase algae growth) to your aquarium water. TIPS AND RISK-FREE GUARANTEE! You will receive our PROFESSIONAL CLEANING INSTRUCTIONS INCLUDED with your filter socks. In addition, we are committed to our 100% CUSTOMER SATISFACTION, so if you find that you are not 5-Star happy with us or our products, please contact us and we will do whatever it takes to make sure you are 100% satisfied.