Better oil resistance, abrasion resistance, acid and alkali resistance, ageing resistance and pliability,the filter lens can be changed according to electric adjustment, flip front lens for easy weld inspection, protects upper chest and throat from sparks and spatter. Product: CKL-3018 auto darkening welding helmet ,welding mask material:Polypropylene Lens size:110*90*13mm Inspect window Size: 90*40mm Switch time:1ms Shade:4/9-13 Ultraviolet protection:<0.0001%(210-365nm) Infrared protection:<0.0001%(780-2000nm) Power:Solar cell with 2 AAA battery Operating temperature:-5°c-55°c Package: 4pcs/carton, 49*46*36cm 3/2Kg PIC: