Yonex Poly Tour Pro 120 is a softer playing poly string. This one is very, very spin-friendly. Power players will love the control and feel they get from all areas of the court. A solid, durable string that is a great choice for aggressive, big hitting players. The new Yonex Poly Tour 1.20 17 tennis string is a polyester monofilament created in a specific way to provide excellent durability while also helping to reduce arm fatigue. This string also features a high repulsion power.