10 pack inside & outside polycarbonate for 4x5-Inch & 5x4-Inch helmets. Inside protection plate for all Carrera ADF helmets and for 5000V, 5500V, IDF48 adf's. ArcOne is a manufacturer of industrial safety products including Auto-Darkening welding helmets, safety glasses, hard hats, inverter power sources and Respiratory protection products. Most of our products are designed and engineered at our taunton, MA facility. ArcOne is well known for being innovative with both technology as well as the marketing of all its products and has been a major force in the evolution of the Auto-Darkening welding helmet business since 1992.