Like all Vendoth ships they were equipped with shields that solidified when hit by weapon fire. This outer shell then acts as a sort of bandage over the damaged portion of the shield, allowing it to be repaired.
They were also armed with a type of energy weapon that when fired appeared like a plasma burst. Its effects however were very different: When it came into contact with another ship's shields, it solidified that area of the shields. These weapons' firepower was similar to more conventional energy weapons used in the Alpha Quadrant. (Star Trek: Unity (crossover))