Located in Alpharetta, Georgia for over a decade, ISPRING water systems LLC is a family owned company specializing in reverse osmosis water filtration systems. Our products include residential and commercial reverse osmosis (RO) systems, whole house water systems, Ultra filtration systems, shower filters, faucet filters, counter top filters, filter cartridges and housings, and kitchen faucets and fittings. Our aim is to make high quality drinking water accessible for all households. With affordable pricing, solid quality, prompt delivery, and top notch customer service, we hope to assist in bringing you great water for years to come. Our filter (FM15B) is specially designed for iron and manganese removal, reducing iron (Maximum 3.0 ppm down to 0.01 ppm) and manganese (Maximum 1.0 ppm down to 0.01 ppm). Being a perfect 2nd stage filter for ISPRING WGB21BM, FM15B also fits standard 10 in. x 4.5 in. housings from most brand name models. The cartridge lasts up to 3 times longer than conventional media. It also has a minimum impact on water flow (up to 15 GPM) and requires minimum maintenance.