Ask the seller.
But an auction lot can consist of a single item (even if the item normally appears in a set)
CANADA 1999, "MILLENNIUM - HOLOGRAM" FULL PANE OF 4 STAM, MINT NH.
or a huge quantity of items
GIRLS Size 7/8 SUMMER Clothes LOT Shorts SKORTS Tops JUSTICE Gap CHILDRENS PLACE
So, if it is not clear from the description, ask the seller. It is actually helpful to him, since you are not the only one confused by his listing.