This is a 1.3mm soft co-poly string that feels like butter when you play. The comfort level for this string is unparalleled in a co-poly string, and it is soft and flexible enough that you get great power from the trampoline effect, but also great control because the ball cradles into the string bed, and stays there for what seems like eternity. Because of that cradle effect, you will get a lot more spin than you might have thought. If you like the idea, and the benefits, of a co-poly string, but you have a sensitive elbow, have no fear. This string is much more likely to work well for you, compared to other, stiffer polyester strings. And if you are looking for part of a hybrid configuration that is soft, this is your string. When the ball hits these strings, its almost as if you can just grab it, and then guide it like a missile to whatever part of the court that you want. Like all strings, the feel is very important, and you just have to try it to know what it feels like. We want to make that easy for you.