Independent pupil adjuster, 0-8.0 negative diopters myopia adjustment, provide users with the best field of vision. Note: Headphone with TYPE-C and IOS ports require 3.5mm headphone jack adapter(Not Included)! For iPhone recommended to use the original earphone adapter cable of iPhone (LT to 3.5mm).,Independent pupil adjuster, 0-8.0 negative diopters myopia adjustment, provide users with the best