The Kyropatris Field Generator is a portable defensive shield generator that is exclusively fielded by the Secutarii forces of the Adeptus Mechanicus' Titan Legions. While visually taking the form of a backpack, it is actually fully integrated into a cybernetic Secutarii's ribcage and chest cavity.
This harmonic field generator creates an atmospheric impedance barrier which is capable of deflecting projectiles, blast fragmentation and similar debris before they strike the Secutarii, and at greater field density, even deflecting heavy weapons fire and powerful kinetic waves like an invisible wall.
The secret of this device's power is that a single Kyropatris field generator is alone of little effect, but in proximity to others attuned to its wavelength, the energy form is amplified and woven together with those around it like armoured mail, granting it a defensive potency that allows the Secutarii to endure in the tempestuous and savage battlefields in which they are expected to operate.
- The Horus Heresy - Book Seven: Inferno (Forge World Series) by Alan Bligh, pg. 286