Maybe they mean, "brifters"?


If that's the case, they'll need:

• Right and left brifters
• Front & rear derailleurs
• Cassette
• Chain
• New brakes (because the brifters will have a specific pull ratio for the brakes)
• New brake and shifter cables w/housings

These items need to be generation specific (i.e. you can combine Shimano 5800 with 6800 but you can't combine 5800 with 6700)
Also, they need to be speed specific (you can't use a 9 speed chain with an 11 speed cassette or a 9 speed brifter with an 11 speed cassette)


There are a lot of other caveats like being able to combine different groupset components as long as they are of the same generation and speed but that's just going to get confusing.


Basically you need a new groupset. A compact Shimano Claris would probably do you fine...


...and don't be shocked by the sticker price, even for a take-off set that you find on eBay (spoiler alert: I haven't priced it but I wouldn't be surprised if even a take-off Claris groupset costs more than what you got your bike for).


**edit: I'm assuming that the left brifter will be compatible with the crankset that's already on the bicycle.