915MHZ fiberglass antenna : is a composite of glass fiber and one or several thermosetting or thermoplastic resins, such as phenolic resin, epoxy resin, polyester resin, polyimide resin and so on. FRP, or glass fiber reinforced material, is a new type of composite material developed at the beginning of the 20th century abroad. It has many advantages such as light weight, high strength, anti-corrosion, heat preservation, insulation, and sound insulation. The earliest composite material is glass fiber reinforced plastic or 915MHZ Antenna with magnetic base , in fact, it has nothing to do with steel. 868MHZ Fiberglass antenna does not contain iron at all, nor is it a composite of glass and steel.