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 outer layers - one of which is reinforced with aramid powder and the other treated with silicone. Ultimately, as the softest and most comfortable member of the RPM family, this is a great option for players who want a more arm-friendly control string.