Our propeller filter and adapter designed to fit the GoPro Hero3+ and Hero4 (as well as the Garmin VIRB Ultra 30), this removes the propeller in 90% of the conditions encountered on a typical VFR flight. It is intended for use both in the cockpit or mounted externally on your aircraft. HOW IT WORKS: The GoPro's image sensor is controlled by the amount of light it senses. In normal lighting conditions, the sensor runs faster than the propeller, causing distortion and odd lines in your video. Our filter modulates the amount of light entering the sensor and keeps the speed of the sensor slower than the propeller. Since the amount of light changes constantly and the filter does not, we designed the filter to completely remove the propeller in 90% of the conditions experienced in VFR flight. For best results, we recommend avoiding shots straight into the sun. We have designed this adapter to attach any 58mm lens to the GoPro case. We supply you with a high-quality Neutral Density glass filter from Tiffen for removing the propeller, and you can add your own polarizers or other filters for other activities. Our adapter is milled with precision CNC from aircraft-grade aluminum. This filter is also available as part of our NFlightCam Cockpit Kit for GoPro Hero3/3+/4 COMPATIBLE WITH: Garmin VIRB Ultra 30, as well as GoPro Hero3+ and Hero4 cases. Please check to make sure your case does not have screws on the bezel, as these are the old style cases and will not work with this filter. Not compatible with any other GoPro. *Camera not included