Galvanic Blast is a common Instant card from Scars of Mirrodin (SOM), collector number 91. Current market price: $2.11 (foil $14.74), TCGplayer market prices via Scryfall.
Galvanic Blast deals 2 damage to any target. Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.