i12 headphones belong to what grade

i12 headset belongs to the high-end grade, belongs to the international first-line brand, i12 a is the in-ear headphones under the Infike, the frequency response range is 20-20000Hz. grade refers to the good and bad things of the rank or level. It can be categorized and arranged according to certain standards, usually divided into high, medium and low three levels, such as high-grade, medium-grade, low-grade. This concept can be used to describe the division of things such as commodities, products, wages, etc., but it cannot be used to describe the status of people. For example, the grade of a hospital can refer to its medical equipment, quality of service and other aspects of the grade; while a person's grade refers to its social status, cultural level and other aspects of the level.