The "PK series" refers to a line of products or models that are often associated with a specific brand or industry. This series can include various items, such as electronics, vehicles, or machinery, designed to meet particular performance standards or consumer needs. Each model in the PK series typically features unique specifications and enhancements that distinguish it from other series. In the context of automobiles, the PK series may represent a range of vehicles known for their reliability and efficiency. These vehicles often incorporate advanced technology and design elements, making them appealing to a broad audience. The PK series aims to provide quality and value, catering to both individual and commercial users.