Best robust USB pen for keyring?

[sports_brah]

As per the title, I'm looking for a decent USB pen. I've had a number of fast ones and high capacity ones, but the build quality for lots seems to be terrible.

Thus I'm wondering if people had any decent recommendations for a robust USB pen that can go on my keyring. USB3 preferred but will take anything. Capacity has to be 16gb+ and the price preferably (but not set in stone) under £40.

Thanks!