AUDEW Pro Solar Auto Darkening Welding Helmet Grinding Welder Mask ACF Auto-Darkening welding Helmets are designed to protect the eyes and faces from spark, spatter, and harmful radiation under normal welding conditions. Suitable for high welding operation temperature, good choice for Welding or Grinding Selection. Viewing area: 3.62 x 1.66 in (92 x 42 mm),Fully Automatic Power On/Off. Response time(bright to dark): &lt;1/30000 seconds (normal temperature conditions) Power: Lithium batteries+Solar