The AY-SB and AY-MB Airinx air filters are made with a special dry element and then placed between our dual chrome ABS spiral cages. Our special double-ply element uses 2 layers of 3 dimensional urethane foam (with different textures) to increase filtration and maximize intake airflow. The outer ply has a large opening while the inner rough layer is made up of a fine foam. The outer cage is a spiraled straight-fin design which helps promote air intake. The chrome finish can dress up any high performance engine compartment and is available in two compact sizes AY-SB (small) or AY-MB (medium).