Boston 2018 Overpass Souvenir Package is one of CS2's weapon cases, used to obtain randomly-dropped skins via key unlock.

Cases drop randomly to active players at the end of matches and require a $2.49 key to unlock. The drop tiers follow Valve's standard distribution — Mil-Spec at 79.92%, Restricted at 15.98%, Classified at 3.20%, Covert at 0.64%, with a 0.26% chance of a rare special item (knife or gloves where applicable).

Sealed copies of the case itself are tradable on the open market — tracked across 15 marketplaces, ranging from $30.53 to $299.99.