Abstract: A filtration device adapted for adjustably interlocking with adjacent filtration devices in a filter bank, wherein inversely disposed flaps on opposing sidewalls, such us an upper flap disposed along a first sidewall and a lower flap disposed along an opposing sidewall, overlap to interlock and prevent air flow between adjacent filters. Each flap may comprise a single member, or may include multiple folded sections, and may be color coded or provided with installation instructions, may be manufactured integrally with an air filter frame, or may be formed separately and adhered to the frame prior to filter installation, and a flap may also include an adhesive for adhering interlocking flaps together.

Abstract: A filtration device adapted for adjustably interlocking with adjacent filtration devices in a filter bank, wherein inversely disposed flaps on opposing sidewalls, such us an upper flap disposed along a first sidewall and a lower flap disposed along an opposing sidewall, overlap to interlock and prevent air flow between adjacent filters. Each flap may comprise a single member, or may include multiple folded sections, and may be color coded or provided with installation instructions, may be manufactured integrally with an air filter frame, or may be formed separately and adhered to the frame prior to filter installation, and a flap may also include an adhesive for adhering interlocking flaps together.