Engineered for optimal protection in welding environments, this green glass filter plate is precision ground and edged to ensure a secure fit. With a shade rating of 4, it effectively shields the user from harmful ultraviolet and infrared rays, while maintaining optical clarity for enhanced visibility. Measuring 4-1/2 inches by 5-1/4 inches, this hardened glass lens is a reliable choice for those seeking a balance between safety and performance in their welding tasks. Please note that while it is heat treated for durability, it is not unbreakable and should be handled with care.