Where does Jailbreaker item-set drop in ESO?

Jailbreaker item-set can be *found* in The Banished Cells.

What type of set-item is Jailbreaker?

Jailbreaker is a(n) Dungeons item-set.

Jailbreaker (ESO Sets) - GuildPlanner.Pro

Jailbreaker

Type

Dungeons

Means to Obtain

The Banished Cells

Bonuses

(2 items) Adds 1032 Maximum Stamina
(3 items) Adds 121 Stamina Recovery
(4 items) Adds 121 Stamina Recovery
(5 items) Adds 133 Stamina Recovery
(5 items) Gain Minor Expedition at all times, increasing your Movement Speed by 15%.

Pieces

Medium (All)
Shield
Weapons (All)
Neck
Ring

ESO Set