With  the introduction of RPM Soft, Babolat brings unprecedented comfort to the RPM family.  Unlike a stiff polyester monofilament, this string is constructed with a uniquely flexible polyamide core, giving it the most arm-friendly response in the RPM line. To help with durability, RPM Soft is built with two co-polyamide layers - one of which is reinforced with aramid powder and the other treated with silicone to reduce frictional notching. Ultimately, as the softest and most comfortable member of the RPM family, this is a great option for comfort seekers who crave a plush and powerful hitting experience.