GN new designed mud mixer is with a shaft to connect the electric motor and gear box. Like the photo below. 
The previous and common design is directly connection one, which is without connection shaft, the motor and gear box is connected directly. This design has small footprint which can save place when it is installed on the mud mixing tank, also it less the spare parts, but according to the jobsite’s feedback, it is much easier to be damaged.
The new designed shaft connection mud mixer has larger footprint compared with the previous one, but it is easier to repair and not easy wear. Clients may have various feedback for these 2 types mud mixer, we will provide according to client’s requirement.