No Zanpakutou
Here is where those that are not much of a threat are kept, since being found guilty by Central Forty Six, as they are stripped of their Zanpakutou, they are placed down below, with all the other low grade offenders.
Not even the guards are allowed to carry their Zanpakutou down here, since there is the chance of having it taken and used against them. Only those with extensive Hakuda training are allowed to come down unattended. This is because they must be able to defend themselves, under any circumstance, in case the prisoners decide to try something.