* Shade number in light state: Din4#
* Shade number in dark state: Din9-13# (stepless regulation)
* Response time: <0.1ms (room temperature)
* Return Time: rapid-0.5s slow-1.5s
* Power supply: Two AAA alkaline batteries (not included) & solar cell (min welding hours: 1000)
* Working temperature: 23°F to 131°F
