Generally divided into three grades, $ 100 two hundred yuan three hundred yuan Low-grade, everything can not be stressed Mid-range, blackened, adjustable color number (how much current can be used), sensitivity and lighten speed adjustment. High-end, all are free stall regulation. Other lenses darkening speed, viewing area of ​​the lens, lens viewing angle, the material of the hat, the hat shape. The advantage is not dazzling speed, savings, especially with both hands. Buy the hat must buy backup inside and outside the protective sheet, a hat with 10, 5. What you pay for, do not understand, and expensive, to be sure.