These are rigs designed to modify the speed, cargo, or inertia/agility of your ship. Usually this is accomplished through a reduction in your armor amount.
Auxillary Thrusters I
Auxillary Thrusters II
Cargohold Optimization I
Cargohold Optimization II
Dynamic Fuel Valve I
Dynamic Fuel Valve II
Engine Thermal Shielding I
Engine Thermal Shielding II
Hyperspatial Velocity Optimizer I
Hyperspatial Velocity Optimizer II
Low Friction Nozzle Joints I
Low Friction Nozzle Joints II
Polycarbon Engine Housing I
Polycarbon Engine Housing II
Warp Core Optimizer I
Warp Core Optimizer II