The Air Handler 2-Ply Panel filters incorporate two distinct filter layers permanently heat-sealed around a galvanized, 9 gauge internal wire frame. The first layer acts as a high-porosity impingement filter and the second as a durable strainer to prevent unloading or streaming. This filter achieves a high level of efficiency on a wide range of particle sizes. The Air Handler 2-Ply filters approach or exceed the performance and service life of rigid, pleated filters. They offer the additional advantage of being linkable, and the self- gasketing, friction-fit frames can often eliminate the need for extra mounting hardware. The 2-Ply filter offers approximately three times the life of fiberglass disposable filters. When used as pre-filters, these filters will add substantially to the life of more expensive high efficiency filters.