For orders with a large variety of goods, we will  make packing lists and affix labels with corresponding codes on each kind of goods to help clients check the goods after receiving the goods.

But for items which with same appearance ，only voltage/RPM/ or other parameters different, such as motors  with different RPM, the label  only  with  code may not be enough to distinguish

If necessary , you can contact your sales to label them as code+style /parameters. Such as below:

In this way ,will help you identify the goods more easily and save some testing time.