What are these tiny pieces of metal that came with my Giant TCR Advanced 2? Last year I bought a 2016 Giant TCR Advanced 2. With the documentation in a small plastic bag came these two small pieces of metal with a spongy sticker on them.




One is slightly curved the other is flat.

What is their purpose?
These are to protect your frame from the support bolt on Shimano front derailleurs (I don't know if SRAM have the same).

You can see them on page page 7 of this manual.