Stronghold the Moving Fortress (Common / Short Print) - Battle Pack 2: War of the Giants Unlimited

Special Summon this card in Defense Position as an Effect Monster (Machine-Type/EARTH/Level 4/ATK 0/DEF 2000). (This card is also still a Trap Card.) While you control a face-up "Green Gadget", "Red Gadget", and "Yellow Gadget", this card's ATK becomes 3000.