This new upper part technology G-CORE stabilizes or stiffens the upper part by approx. 65% because a fiberglass strengthens the wood inside the upper part. The fiberglass encased a solid wood core in the middle of the top and around this encasement is Canadian maple again, this gives a familiar, solid, soft feel, but this can be carried out much more precisely and with less vibration, since the deviations are reduced significantly were. This strengthening is only necessary in the upper area of ??the upper part; about 12 - 15 cm from the leather! The diameter of the leather is 13 mm.The additional CT technology used to guide the cladding of the solid wooden core down to the adhesive leather; - this means that the entire ferrule is reinforced with fiberglass on the inside - lets your shock "dampen" or less vibrations occur and thus less deviation arises / can arise.Navigator Premium multi-layer leatherThis layered leather is basically a hard leather, but after it has been roughened or shaped, it is rather a medium leather in its properties and on the outer edge, due to smaller layers, it reacts e.g. more like a soft one with the spin game. The bottom layer is colored red to inform the player; it would be time to replace the leather, at the latest when he can clearly see this red layer.