Marathon 3 Golf Balls Engineered for distance and durability, the Srixon Marathon Golf Balls feature a large, highly resilient Energetic Gradient Growth Core that delivers explosive ball speed. Features: Advanced Energetic Gradient Growth Core construction promotes seamless energy transfer to maximize distance and optimize ball performance on every shot Strong ionomer cover offers enhanced durability for longer performance and value Swing Speed: All Launch: Mid-High Greenside Spin: Mid Construct