This handy clip lets you keep your Fitbit Flex around your neck, or on a keychain. The Fitbit snaps in securely, but can be removed for recharging just by pressing on the back.
The hole is 4mm in diameter.
If you like the hole in a pendant to go the other way, you will want to see this version with a
built-in chain.
There is also a
customizable watchband clip version.