Regarding quality of Freewell filters. I was given a set for my H by a vendor, I never used them because they were horrible...but wait there's more. So I reluctantly bought the "all day pack" of Freewell filters which is the same they sell for the 520 they cost for $99 at Carolina Dronz (currently out of stock). I bought them because since I was going to Iceland I had to get something for ND with the snow etc. I reluctantly bought them. Long story short Freewell this time around has really created some fabulous filters which I would highly recommend unlike what they had for the Typhoon H. Their color accuracy has been dead on and the set included ND 64 the $99 package includes 8 filters. Here is their propaganda "The Yuneec H520 E90 8 Pack from Freewell include all essential filters you require to shoot in daylight condition from cloudy day’s to bright sunny day’s this kit include 5 ND filters ND4, ND8, ND16, ND32, ND64 which are helpful in cutting the light coming to your camera sensors which helps in naturally blurred motion while the camera is moving. The CP (Circular Polarized) lens filter from Freewell is best for preventing glare from natural reflective surfaces to enter the lens and give clear and sharp images outdoors in the daytime. The UV filter is best for preventing the sun’s ultraviolet (UV) rays from entering the lens These lens filters are designed to be lightest in weight and offer you effective solutions for filming in sunny to very bright sunny conditions."