The Fusion Core is a cylindrical power source with a glowing blue interior, encased in a metallic shell that shows signs of wear and rust, typical of post-apocalyptic salvage. The core features a series of ribbed grooves along its length for grip and cooling, with a prominent status display on one end that flickers with remaining energy levels. The exterior is a mix of dull metal and scorch marks, indicating heavy use and exposure to harsh environments.