●G10-FR4 is a fire rated electrical-grade dielectric made with and epoxy material reinforced with a woven fiberglass mat. FR-4 is an abbreviation for Flame Resistant 4. ●Sturdy material for printed circuit boards and RC model ●An outstanding insulator.High strenght ●Mechanical properties plus high resistance to flame, heat, arcing, and most strong alkali solutions. Can work under humid or moist conditions ●Package include:1pcs sheet