I use the tiny USB stick on my keychain and to avoid having it filled up with dust I designed a cap to cover it up.
you can buy the Stick here (amazon link)
I also used some para cord to hang it on a keychain, the stick doesn't come with any kind of cap or lanyard
there are two files, one is a pretty good fit if your bridging is perfect, the other one has a bit more play to compensate for an imperfect bridge
The author marked this model as their own original creation.