Basic Resistance Armor

"The Spectral Armor is a reusable panel with built-in resistance to Energy weapons. It can safely absorb excess energy."
 * -|Spectral=

"The Shockwave Armor is a reusable panel with built-in resistance to Explosive weapons. It can diffuse explosive force."
 * -|Shockwave=

"The Deflector Armor is a reusable panel with built-in resistance to Kinetic weapons. It can deflect kinetic projectiles."
 * -|Deflector=

General
The Spectral, Shockwave and Deflector Armor are similar to Zynthium but have the added ability to reduce incoming Energy, Explosive and Kinetic damage respectively.

Advantages
Civil War Armor is slightly more efficient than Zynthium against the respective damage type. Refer to here about when to use each variant.

Reading this is also recommended for a better understanding of how resistance is calculated from multiple pieces of resistance armor.

Disadvantages
Considering equal damage taken from Energy, Explosive and Kinetic sources, Civil War Armor is actually less mass efficient than Zynthium. It only works if you specialize your ships to only fight against certain types of targets.

To add insult to injury, the XP per health is also greater, setting your fleet up to be attacked by stronger ships.

Trivia

 * The Spectral Armor was named after the Energy-resisting Spectral Shield.
 * The Shockwave Armor was named after the Explosive-resisting Shockwave Shield.
 * The Deflector Armor was named after the Kinetic-resisting Deflector Shield.
 * Together, the Civil War Armors represent the first armor pieces to feature resistance against a single damage type.