FMI Pro-Pleat Pleated Filters MERV 8 (1″ 2″ 4″) (12 pk for 1-2″, or 6 pk for 4″)
All filters are built nominal, with up to a 9/16″ undercut on the length and width, as is standard for filter sizing. 2″ and 4″ filters have a 1/4″ undercut on thickness, 1″ filters have a 1/8″-1/4″ undercut on thickness.