Nylon String Wound Filter Cartridges are used in special process applications, concentrated alkalies and hydrocarbons. They are spun wound to micron ratings from .5 to 200 and are manufactured in our facility in Coleman, TX. Excellent micro-organism resistance. For use to 300ºF. String wound filters are a 'depth' filter created by winding diamonds onto a core with 1" to 4" of filtration media. Depth Nylon filters provide a high dirt holding/retention capability with low media migration.