Premium Imported Quartz Crystal Material: Crafted with selected high-quality imported quartz crystal, boasting exceptional optical, thermal and mechanical properties for long service life in harsh industrial environments.Extensive Multi-Spec Options: Available in a full range of D40 series (401.5/2/2.5/3/4/5/7/9mm) and other sizes (423/4/9, 432, 453, 46*2mm), meeting diverse replacement needs of fiber laser cutting and welding machines.1064nm Wavelength Optimization: Precisely calibrated for the 1064nm fiber laser core wavelength, ensuring maximum laser energy transmission efficiency and optimal cutting/welding performance.Double-Sided Anti-Scratch Wear-Resistant Coating: Professional double-sided plating with enhanced light permeability, effectively reducing laser energy loss and resisting scratch, wear and laser ablation for stable long-term use.Superior Thermal & Laser Resistance: Excellent thermal stability and high-temperature resistance, able to withstand extreme temperature changes and long-term high-power laser operation without deformation or performance degradation.Blue Light Protection Design: Added high-efficiency blue light filter factor via professional processing, providing extra eye protection for operators and reducing laser blue light radiation harm.Strong Anti-Pollution & Anti-Splash Performance: Acts as a reliable barrier to block metal splashes, dust, welding spatter and debris, protecting internal precious optical components and reducing equipment maintenance costs.Ultra-Precise Dimensional Tolerance: Strict size control and precision processing, ensuring a seamless fit with laser cutting/welding heads and no modification required for installation.Tool-Free Easy Installation: Simple manual installation and replacement steps without complex professional tools, saving maintenance time and reducing production downtime.In-Stock for Immediate Shipment: 5 brand new pieces in stock with standard worldwide shipping, meeting your urgent replacement and equipment maintenance needs efficiently.