Solinco Tour Bite 4-Sided Polyethylene Tennis Racket Strings are the best choice for the professional or advanced player seeking greater control, great spin potential, and durability in their string choice. They are often used as one half of a hybrid setup, usually with a softer string like a multifilament to increase playability without sacrificing too much durability. Length: 40ft. Composition: Copolyester monofilament. Durability: 8 out of 10. Spin: 9 out of 10. Playability: 7 out of 10 Power: 6 out of 10 Comfort: 7 out of 10.