The J Tool is used to disengage the dead bolt on a locked door from outside of the protected space. Usually, the ability to use this tool is dependent upon a sufficiently large gap existing between adjacent doors (on double doors) or the door and jamb (on single doors). The tool is slipped between the gap and the u-shaped end is used to make contact with the deadbolt thumb screw. Once contact is made, the base of the handle is rotated to disengage the deadbolt. This tool is small enough to be concealed under a shirt and an improvised crash bar tool can be made using a carpenters square. Door fitment can be adjusted using the pry bar or the air wedge included in the physical kit.
Instructional videos describing use of the tool are listed below.
Lock Picking Lawyer usage video: https://www.youtube.com/watch?v=1ciqsCJD3f0