I don't have a kayfun because I don't like that it is plastic...and the metal piece doesn't allow you to see your juice level.
Your KFL clone didnt come with both the clear and chrome/metal center cylinders? Mine did, and with all extra parts and a long pin squeeze bottle for filling. The fogger V4 has a glass center piece, and honestly is the best RTA I have used, even over the kayfun and the Aqua. No comparison. Its VERY impressive.