Dullahan D4 is an Energy Layer released by Hasbro as part of the Burst System as well as the SlingShock System. It debuted in western countries with the release of the Dark-X Nepstrius N4 & Dullahan D4 Dual Pack.
Hasbro's Dullahan D4 is a Balance Type Energy Layer that's primarily round in shape. Its design consists of four large blades that create an overall round, diamond-like shape, akin to a rounded and reversed Luinor L4. Each of these blades are slightly lowered at the fronts, and slightly raised at the ends, with each one having a small protrusion at the front, a small one on the front side, and a small and large one at the ends, while the middle of the blades is round and smooth. In the center of the Layer are two armored heads on either side that are from a sideways profile; both resembling the helmets of knights. These details represent the Layer's namesake: Dullahan, the headless horseman of Irish mythology. As a part of the SlingShock System, Dullahan D4 features regular plastic instead of metal in its design; in this case, each of the four blades have metallic-painted plastic on top of them. The inclusion of plastic makes Dullahan D4 fast enough to ride the Rail System of SlingShock System Beystadiums, albeit at the cost of being lighter than most SwitchStrike Layers.
Akin to most other Turbo Layers, Dullahan D4 is compatible with a Level Chip that can be fitted underneath the Layer.