This is a bundle of the Zephyr Safety Flanges and the Zephyr CFPREX 2" Airway Buff Extender Kit. Airway Buff Safety Flange. Zephyr introduces our new "State-of-the-Art" Airway Buff Safety Flange Kit. Zephyr develop these High Tech, Lightweight, yet durable Flanges. Flanges are molded from High Density Composite Nylon that are lighter, yet stronger than aluminum.