A CES is where a shipment will be trucked if CBP has pulled it for inspection.

What is a CES?

A CES (Centralized Examination Station) is a privately operated facility designated by CBP for physical examination where imported or exported cargo is made available for a Customs inspection. 

Shipments selected for a Tail Gate or Intensive exam will be trucked to a CES. 

The importer is responsible for all costs associated with a Customs exam, including trucking to and from the CES, the CES fee, storage, etc.