Hive Prisoner Shackles are shackles specifically for Hive and Skeleton prisoners since they do not have a boots slot and cannot have regular Prisoner Shackles equipped, as well as Human or Shek characters who have prosthetic legs. Though any character can wear them, regardless of race or limb status. These shackles are instead equipped in the armour slot. They have a lock level of 20 and a strength level of 20.
They may be used to train melee attack and defence but please note that a character will be considered "enslaved" by the game once they equip the shackles so one would have to deal with the whole escaped slave mechanics after training.
This armour has inventory dimensions of 3x4.
Have one of your hiver or skeleton teammates be a slave and have them pick their own shackles. Any other attempt at having someone else pick shackles either to a teammate or some other slave just has them disappear as soon as they are unlocked.