4mm/12mm S-hook

A simple S-hook.

* The small hook has inner diameter 4 mm with a 2 mm opening.
* The large hook has inner diameter 12 mm with an 8 mm opening.
* The eyelet is meant to attach a pull string and has inner diameter 3 mm.

The part flexes slightly, so it holds in place when hooked onto an object. In the photograph, it's hooked around a 4 mm elastic cord and a 10 mm metal bike rack.