The CLL-series encompassed a group of binary loadlifters whose limited cognitive abilities barely allowed them to be classified as droids. These models were typically assigned to the most basic loading operations, with more sophisticated labor droid models being necessary for more intricate work. One example within this series was the CLL-M2 binary loadlifter manufactured by Cybot Galactica; despite its launch occurring shortly before the Separatist Crisis, it was remarkably similar to earlier droids that existed far back in droid history, almost to the equivalent of prehistoric times.
The CLL-series made its initial appearance in the prequel trilogy movie Star Wars: Episode III Revenge of the Sith, released in 2005. Within the current Star Wars canon, the series was officially recognized in the 2015 publication Star Wars: Build the Millennium Falcon 20.