The manager is an upgrade for the Sell Center. The upgrade has 3 levels which grant different benefits as listed below.
Managers increase offline progression by 25% per level.
Level 1 allows the user to lock an arbitrary amount of minerals and isotopes such that they aren't sold when you click sell all. Also allows for Offline Progression, where you'll receive 25% or your normal progress for 12 hours.
The lock is activated by clicking on the lock beside the sell button for each resource and inputting an amount of resources to keep when selling. If you have more resources than you have locked, the excess amount will be sold. If you have less than the amount you have locked, no minerals of the given type will be sold. To disable the lock you have to input 0 as the amount in the lock interface and click update. There is no limit as to how many locks can be active, i.e. you can have a resource lock on every single resource.
Grants a small increase of finding rarer materials (excluding the isotopes). Increases the effect Offline Progression, where you'll receive 50% of your normal progress for 24 hours. it drops from a golden chest at random. (E.g. a player got Lvl.2 Manager from a golden chest at 900 km).
The level 3 upgrade
increases the chance of miners finding normal treasure chests. Increases the effect of Offline Progression, where you'll receive 100% of your normal progress for 48 hours. it drops from a golden chest at random. (E.g. a player got Lvl.3 Manager from a golden chest at 1072 km).
During Offline Progression it will only count towards your depth and the ores/isotopes that are mined. No chests will be gathered during offline progression (however, they will appear in the chest collector) and also no fights from monsters will be included in offline progression.