The Omnipure K-Series K5520P-JJ inline filter is a 1 micron carbon block filter. This filter has 1/4 FQC fittings. It also includes a phosphate inhibitor. This can also be used as a post R.O. filter. This filter can be used in ice makers, refrigerators, beverage equipment, drinking fountains, under the counter systems, R.O. systems and in conjunction with purification systems. Reduces: Particulates Class 1 Additional Details ------------------------------ Product description: The Omnipure K-Series K5520P-JJ inline filter is a 1 micron carbon block filter. This filter has 1/4 FQC fittings. It also includes a phosphate inhibitor. This can also be used as a post R.O. filter. This filter can be used in ice makers, refrigerators, beverage equipment, drinking fountains, under the counter systems, R.O. systems and in conjunction with purification systems. Reduces: Particulates Class 1