Mainstay of the Separatist Fleet. They tended to have many of these in almost every action.

You know, this kinda makes her look like Echo in Season 7

Modular decentralized design with an exclusively droid crew made them harder to kill than they had any right to be. Also excessively easy to deconstruct and salvage, combining large component parts of multiple ships to make a "new" one with relatively little time and effort. Knocking them out was hard. Keeping them down was harder.