These are nail tips with a cavity. They may be used to create any 3D encapsulated design. Simply insert glitters, dried flowers, charms, gems and cork to seal. The empty nail tip comes with a cork. You can fill the nail with liquid, gems, glitter, microbeads, foil shapes, or other decorative items, then apply the cork to seal the tip. The tips don't have to be used to create aquarium nails. Use them to create sand art designs, encapsulated flowers designs, or any encased 3D design.