Step up your power game with the Yonex Poly Tour Force, the most explosive co-polyester string in the Yonex Poly Tour lineup. Built for players who attack — aggressive baseliners, big hitters, and anyone who wants free pace on every swing. Yonex reworked the formula with a softer co-poly core that grips and pockets the ball longer at impact, then releases it with serious energy return. The result is explosive power and a lively response you can feel on every stroke, while the firm, slick monofilament surface snaps back fast to generate heavy topspin and biting slice. Despite the power, Poly Tour Force keeps you in command. Its controlled, low-launch trajectory rewards a full, fast swing — load up and go for your shots knowing the ball will drop in. And because the construction is softer than a standard polyester, you get more comfort and ball feel without sacrificing the durability and tension stability that define a true tour-grade string. Available in three gauges — 16G (1.30mm) for maximum durability, 16L (1.25mm) for the all-around sweet spot, and 17G (1.20mm) for the most feel and spin — and in striking Ruby Red and classic Black. Ideal as a full string bed or as the poly half of a hybrid setup. Best for: Intermediate to advanced players, aggressive baseliners, and strong ball-strikers seeking power, spin, and control in one string.