The Stretch Goals Box contains all the rewards that were unlocked as part of the Gamefunding campaign on Gamefound.

The Stretch Goal Box, for example, adds several new playable missions, new weapons and artifacts, additional Stalker miniatures, plastic markers, new monsters with their miniatures and related equipment, Maps & Stickers Recharge Pack, Magnet Artifact Die which allows you to customize your anomaly exploration by rolling the die for specific effects, opening new possibilities and increasing your chances of extracting valuable artifacts from the depths of the Zone, and much more!