Babolat RPM blast is one of the most popular strings in tennis right now. It's popularity is based on the fact that Rafael Nadal has been a long time user of this string. It is considered a co-polyester monofilament string that offers very good control and spin for advanced players. It is a firm feeling string that allows players to swing with long fast strokes and maintain spin and control. It is also a very durable string. All in all, RPM Blast is a string that advanced players looking for a boost in control and spin without having to worry about breaking strings. , The RPM Blast polyester string is geared towards producing good spin while providing durability in the string. This is the string that Rafael Nadal and Carlos Alcaraz use. Very popular string for those that use Babolat Racquets.