Stalcraft Wiki: Bale Bag

In-game description (EXBO)

A Research Institute 7 development based on captured Trailblazer gear. The container section uses an assembly layout typical of the KZK series, allowing the Sheaf’s design to be optimized into a more ergonomic form and turned into a full-fledged bag capable of carrying more than just artifacts. However, this came at the cost of reduced container capacity. The engineers who worked on the new product note that some of the Sheaf’s technical solutions are similar to those found in other relic technologies discovered in the Zone.

Quoted from the game's own text in EXBO's public game data. Not written by STALCRAFT Meta.