Cartridge is 4" x 5" and has approximately a 6 square inch viewing area. Variable shades (9 to 12) and shade 4 clear state for hood-down set up. On switch with auto-off feature automatically urns the unit off after approximately 20 minutes of non-use. Sensitivity adjustment allows user to adjust the unit depending on ambient light or arc intensity. Variable shade version includes a "dark to clear" delay adjustment which allows user to adjust for tack welding or bright residual pool.