The PRO Series are the next step in bowstring performance. No over servings, tight measurements, high tension in the string during serving for consistent, uniform response in your recurve bow and a distinctive feature of high quality strings, are standard on the Pro series strings. The Flex Bowstring Fast Flight Plus Recurve Pro is a qualitative string from the Spanish manufacturer String Flex. Key features •Filament materials : FF+ (HMPE) •Serving Materials loops and centre : Poli-braided material. (Colour may vary) •Comes in clear plastic tubes for better protection and conservation