Group Tester one (GT1) provides all diagnostic operations of control units of BMW vehicles till model year 2008. Encoding and programming of control units can be accomplished with GT1 on vehicles till model year 2005. If you want to program vehicles from year 2005 and above you will require BMW OPS or BMW OPPS unit.
GT1 unit with DIS software is used for diagnosis, with SSS software is used for programming.