The MSE-4 droid was a fifth-degree general-purpose labor droid produced by Rebaxan Columni prior to the onset of the Clone Wars. The MSE-4 looked almost identical to the later model MSE-6 droid, only much smaller. These tiny droids were produced as part of a test run that, along with the MSE-5 droid, led to the creation and success of the company's MSE-6. A number of MSE-4s were employed by the Confederacy of Independent Systems on Mustafar, working in a Techno Union facility.