BMC Flat Panel Replacement Air Filter 2007-09 Porsche 911 (997) 3.6L GT2 / RS / Turbo / 3.8L GT3Performance BMC air filters are designed and produced to ensure a higher air flow than original paper filters. In F1, for example, BMC cotton filters minimize the loss of air flow pressure passing through the air filter; this way ensures the best conditions for full exploitation of maximum power. Therefore the benefits of replacing the original paper filter with BMC cotton air filter, produced using the same technology and materials as the F1 air