... : aluminum 4. Factory direct price 5. Paypal available High Quality Aluminum LED BoardManufacturer Specifications:Number of Layers: 2-layerBase Material: AICopper ... 28 layersMaterial type: FR-4, CEM-1, CEM-3, High TG, FR4 Halogen Free, RogersBoard thickness: 0.21mm to ... Gold, Immersion Silver/Gold, OSP, Gold plating Solder Mask Color: Green/Yellow/Black/White/Red/BlueTolerance - Shape tolerance: ±0 ...