I've recently bought a 17 plate CBR 125 but I'm curious what exhausts can I fit to it?

 

Lots of exhausts out there , but first take a look as to how a new exhaust might affect you Bikes warranty and your Insurance in the case of an accident, some firms will default on payments due to modifications

 

As Bill says lots Of aftermarket cans available, none will give you any additional power, most will be of inferior quality but most will make a bit more noise and be a bit lighter. On a newer bike like yours you’ll find the original exhaust is the best option. Mr Honda spent a lot of money getting it spot on!