You can. They are just clear rubber earring backs. Those particular ones I got at Michael's craft supplies. They come in a package that looks like this:
You also have to plug the hole in the earring back with something. For that I used what is called a head-pin (also a jewelry finding, can get at Michael's). This is what they look like:
1" Silver-Plated Headpins - Fire Mountain Gems and Beads
You have to trim the head-pins off with a wire snipper after you put them in the earring backs.
Glad you like the
tanks.
If you are a DIY kind of person and want to make your own
tanks, search for a thread called 'home made syringe
tank, looks easy'. A bunch of us posted all about these. Lots of good ideas and variations.
Leigh