Holon Research Tower (EX Delta Species 94/113)

Each player's basic Energy cards attached to Pokémon that has δ on its card are both their usual Energy type and Metal type but provide only 1 Energy at a time. (Has no effect other than providing Energy.)

Card rule

This card stays in play when you play it. Discard this card if another Stadium card comes into play. If another card with the same name is in play, you can't play this card.