Cassion is a manufacturer of electronic components, particularly those in high demand for the aeronautics and astronautics industries.
Most people don't give a damn what parts are in their tech until it blows up on them. However, mechanics and professional vehicle enthusiasts agree that Cassion parts are very good for their cost. While most of their product line targets the aircraft and spacecraft industries, some of their components (particularly capacitance units and batteries) are also used in terrestrial craft, and occasionally in energy weapons.
Cassion is considered a direct competitor to other vehicle parts manufacturers, but doesn't really compete in the aftermarket market; most of its sales are to vehicle manufacturers or do-it-yourself mechanics. Of note is that Cassion sponsors a variety of energy weapons development companies despite ostensibly not being in the business of developing these weapons themselves.
Cassion generally sells component parts, and as such is an ideal company to shop from when repairing a damaged piece of electronics (or looking to build a new one from scratch.)