20x20x4 Exact AC ) ( Pleated 19 1 2 MERV Furnace 3 3 4 3 Air Glasfloss by x 10 Filters Industries. Pack x : 19 1 2 It is 180 all round adjustable It is 180 all round adjustable and ensures no blind spots combined with the included headband and bracket Includes a quick release tab to easily charge and install the battery without moving the device Made in the USA Comparable to MPR rating 600 to 800