I've been looking for a Type A / Type C combo stick for a while to carry on my keychain. This device appears perfect, it is a single drive with type A on one side and type C on the other with either end able to stick into a cap which has a hole to allow a keychain lanyard to be attached.

Good quality. Easy to use. It has come in very handy for transferring files from my mobile to device that don't support wireless transfer but have USB.