Filters can be manufactured in diameters from 800 to 2.400mm with top lid and a manhole on AFM® ng is a unique self-sterilising and fully bio-resistant filter media that was developed to prevent the formation of harmful volatile disinfection by-products such as Trichloramines and THMs. AFM® ng filters particles down to 1 micron, provides substantial backwash water savings and outlasts all other filter media