We use the PCX brand to denote products procured by Pololu with some customization but without substantial design, engineering, or manufacturing contribution from Pololu. As such, products branded as PCX are somewhere between Pololu-branded products and products identified as Generic. Examples include our mini plastic gearmotors; the left item below with a spline shaft might otherwise be categorized as Generic because such motors are available from various manufacturers, but for consistency across similar products we categorize it as PCX because we also have customized versions with D shafts and with extended motor shafts for encoders, as shown below on the right.
PCX-branded items are more likely to be customizable than Generic products because they usually represent products where we have closer relationships with the factory making the products. We typically do not disclose our sources for PCX-branded items; please contact us if you are interested in customizations or other special orders.