Filter An improved enlarged air intake filter for a Bi-Pap machine. Air intake port on the lower right corner on the back of the machine. Closeup of the intake port. Dirty used filter Clean fresh filter Reusable foam filter This is the currently used filter set. Foam on the outside and paper mesh on the inside. As a part of the new filter design –dense foam seals the inlet port and contains the adapter tube. Interior view of the inlet port dense foam seal. Side view of the inlet port dense foam seal and adapter tube. Inlet manifold created with lexan on baseplate to fit under Bi-Papmachine and secure it. 2 piece filter unit constructed of 2 separate filters (details shown below). 2 piece filter unit secured to the manifold by twist fitting – 1 of 2 units. Both filter units attached to manifold. Manifold unit approaching connection to inlet port adapter tube. Manifold attached to the inlet tube. Final appearance of the filter attached to the Bi-Pap machine. Outer filter. Details of capabilities of Outer filter . This is the primary filter.