Neiko 53934A Auto-Darkening and Solar Power Welding Helmet for TIG/MIG - Skeleton Skull Flames Auto-Darkening & Solar Power Welding Helmet For TIG/MIG Battery powered with solar-assist for long life Lens darkening reaction is 1/25000s Working temperature: -5C~55C (23F ~ 130F) Lightweight well-balanced design fully adjustable headgear provides comfort and reduces fatigue