Wattcube is a Equip Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Wattcube is Unlimited.
YGOPRODeck lists Wattcube for these formats: Duel Links, Common Charity, TCG, OCG, Master Duel.
Wattcube belongs to the Watt archetype—use that tag when searching for engine pieces and tech options.
A listed print of Wattcube appears in The Shining Darkness (TSHD-EN054) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Wattcube is about $0.09 on Cardmarket (prices change frequently).
