Stalcraft Wiki: KZS-MU Container

In-game description (EXBO)

A factory-produced set of three KZS-U containers. The reinforced version of the KZS-M was expected to be released before the KZR series containers; however, the work to increase overall volume took too long.

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