Protective lens made of JGS1 fused silica quartz for handheld laser welding and cleaning head. Size 18 x 2 mm. Material JGS1 fused silica with AR coating 1064-1080nm. The lens protects the internal focusing optics from fumes, smoke and metal splashes during welding. Welding heads usually have 2 protective lenses (upper and lower), the lower one wears out faster. Lifespan approximately 40-80 hours of welding, less in dusty environments. Change when you notice stains, burns or deterioration of weld quality. A damaged protective lens can destroy a focusing lens worth 70-150 EUR. Preventive replacement is always cheaper. Suitable for most Chinese handheld welding heads (SUP, Weiye and compatible). We recommend having at least 5 pieces in stock.