Product Name: CHAMPION'S CHOICE DUO TENNIS STRING - SETProduct Code: WRZ997900Overview:Champion's Choice Duo Tennis String is the string combination preferred by tennis legend Roger Federer. This hybrid set combines Wilson's Natural Gut (16/1.30) for power and feel with Luxilon's ALU Power Rough (17/1.25) for durability and spin. Federer typically strings Natural Gut in the mains and ALU Power Rough in the crosses to achieve a softer feel and excellent playability. For enhanced durability, the ALU Power Rough can be used in the mains.Key Features:Professional Preference: Roger Federer's string choice.Hybrid Composition: Combines the power and feel of Natural Gut with the durability and spin of ALU Power Rough.Optimized Playability: Provides a softer feel and superb playability.Versatile Stringing Options: Natural Gut in mains and ALU Power Rough in crosses for feel; reverse for durability.Specifications:Gauge: 17/16Thickness: 1.25 mm (ALU Power Rough) / 1.30 mm (Natural Gut)Length: Set: 40 ft / 12.2 mModel Number: RZ99790