“Different hardness 2 layer structure” which changes flight.
The different hardness two-layer structure changes the grip common sense.
By hardening the first layer of 399 star base, it reduces the twisting at impact.
The star base is also effective in reducing slippage.
The soft surface of the second layer provides a snug fit. With a star-shaped base and surface softness, it is hard to twist and slippery, and it has a feeling of fit. Because it is an elastomeric resin, it is resistant to rain and sweat and exhibits its original performance just by wiping it when it gets wet. Obtained patent and utility model.