The Eternal Sharp tip features a free-spinning tip attached to a metal shaft which is held by the Perfomance Tip.
The part was one of the most heavily anticipated parts in the MFB lineup when first announced, but ES is actually a hugely disappointing part in terms of performance.
Firstly, ES lacks a metal bearing, which would significantly reduce the friction between the free-spinning tip and the rest of the Performance Tip. All of the best free-spinning tips, notably Bearing Core, had NSK Shield bearings which allowed unhindered spin.
Secondly, Beyblades using ES are easily destabilised due to its sharp tip. As all Sharp tips do, Eternal Sharp also has trouble regaining balance, hence making this a poor choice for Stamina. That said, ES still remains superior to BS and S as Stamina Bottoms.