The VL1002 is the 3rd stage MERV 6 vapor-lock carbon filter for Abatement Technologies, Inc.'s CAP1200, and CAP1200-UVP Central Air Purification systems. The actual size of the VL1002 air filter is approximately 15 1/2" x 16" x 2". The VL1002 air filter has woven activated carbon media for absorption of gases and odors. The manufacturer recommends you change the VL1002 carbon filter every 6 to 12 months under normal operating conditions