Ah...so that might be what the Mecha Box Renewal means. AA battery to replace the C and a two speed motor. Maybe Mecha Box renewal is defined as the mechanical motor has been replaced along with using a AA battery whereas Chassis Renewal just means using a AA in the place of the C battery like on the Bullet Trains.
![[Image: 7071.gif]](https://www.allsmileys.com/files/sweetim-texticons/7071.gif)
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