Though possessing heavy particle shielding, YM-2800 were not equipped with ray shields.
As a mining vessel, the limpet was designed to attach itself to the surface of a planet or an asteroid, then use plasma beam cutters to cut through the rocky surface to valuable materials below. However, Rebel Alliance came up with the idea of using these ships to breach and board enemy space vessels. Usually it was freighters and storehouses that were assaulted, but occasionally military vessels were attacked as well.
They were also used to deploy Alliance Special Forces SpaceOps into enemy ships.