Nflightcam Propeller Filter for GoPro Hero Session Metal cage designed for high-speed and high-impact environments where failure is not an option Intended for use both in the cockpit or mounted externally on your aircraft Includes 52mm propeller filter to remove distracting black prop lines on flight video Built-in 52mm adapter allows you to use your own polarizers or filters for other activities Compatible only with GoPro Hero4 Session and Hero5 Session