Lens Type
It comes with either a fixed lens or a variable lens. A fixed lens comes with just one lens that stays the same as you weld, and most manufacturers opt for a number 10 lens. With a variable lens, the shade on that lens will adjust based on the type of work that you do, and many of these welding helmets come with a lens that ranges between at least five different shades.
Auto Darkening
Reaction Time
Adjustable Fit
Sensors
Knob Placement
Knob Size
Extra Padding
Battery Power Type