Up for sale is the gathering Assembly Hall, a rare card from the Mercadian Masques expansion of Magic: the Gathering. These are the Foil, black-bordered, English version.
Assembly Hall: Artifact; spend 4 mana and tap Assembly Hall to reveal a Creature card in your hand; search your library for a card with the same name as that card, reveal the card, and put it into your hand; then shuffle your library; casting cost 5.
These cards are all in at least Very Fine condition, with most being in unplayed, Mint/Near Mint condition.
