Well, if you know why you would need this, then you know it's a necessary piece of equipment for your bicycle repair arsenal. (If not, you probably are not going to buy this item). So, needless to say, it is a fair deal. It's simple to use and if you have any doubt. there are many sites on-line that can help with written instructions and/or videos.
Needed too update shifter firmware on 9200 without wiring to battery. Worked perfectly fine.
I used this to connect my normally wireless shifters to the battery (seatpost) in order to update the L and R shifter firmware. A lot easier than pulling out the battery in the seatpost.
To update 12 speed shifter software, disconnect wire from front derailleur, connect this junction to wire, then connect a second wire to the shifter. Use Shimano software. Boom.
