Solinco Heaven Strings Hyper-G Tennis String. Solinco's Heaven Strings Hyper-G tennis string is a newly developed, high-performance and versatile co-polyester string designed to offer playability and control while generating extreme power and intense spin and bite. Hyper-G utilizes a newly developed chemical formula in combination with the high-powered polyester monofilament fiber designed and shaped to generate maximum power and control while amplifying spin and bite intensity of the ball. 16L Gauge (1.25 mm). Length: 328 Ft (100 m)