 
The 'PTGS' (Police Tracking Gear System) is a K-9 level department group. This is inside the police department, and there are different rooms to be educated.
Xuang Wen Jo is part of this group. This group includes a lot of sirs, madams, and gurus. And of course there are students, and more newer police officers.
All this group decides to complete their tasks are to finish missions, take guru lessons, take shooting skills, solve cases, and earn badges. Some here are always to patrol the whole area of Guangzhou, Guangdong, China.
Lai Li Dian is not part of this group because the level is lower, and to be put into a special group, he is selected to a detective privacy group.
The PTGS group is the fourth highest system group for the police department. This is only for the K-9 level. There are many more training levels than K-9 itself, some lower, some higher or like higher as different police (detective, investigator, investor, police chief, sergeant, etc).