Because everyone in the use of synchronous belt wheel of time, is the need to through the operation of the whole structure of pulley, to drive the rotation of the synchronous belt, and then realize the transmission function. So everyone at the time of buying pulleys, also need to make choice in terms of overall structure. Can have such a request, because for all applications, the structure size is only synchronous belt wheel, can properly installed to the corresponding device, which in turn will be able to realize the normal application. The pulley structure size, is by the structure of the overall performance. So, in order to ensure you buy the suitable size of pulley, you need at the time of purchase, to select the overall structure of the pulley. And different synchronous belt wheel, it will be because the material is different, and the effect of surface treatment and surface, and makes the whole structure has different quality. So in order to ensure you buy the quality is very good pulley structure, also need you to choose the overall structure of the pulley. In short, is to ensure that you buy is better in terms of structure of the synchronous belt wheel, so ask you at the time of purchase pulley, to choose its overall, and choose to focus more on the pulley structure quality and size of these two aspects.