Heavy, silver-colored shackles with a couple links of broken chain dangling from each. Attuning and wearing these shackles will make you vulnerable to lightning damage. However, if you are hit with lightning damage from any source, you become charged by lightning until the end of your next turn.
While charged you gain additional 20ft walking, swimming, climbing and flying speed if you had those naturally or through other means. Your melee attacks deal additional 1d6+2 lightning damage. Enemies gain disadvantage for attacks of opportunity made against you.
You gain vulnerability against lightning damage and resistance against necrotic damage while wearing the shackles.