This tiny terrarium is planted with Leucobryum glaucum.
To care for this terrarium, place in a bright spot out of direct sun. Water with a spray bottle using deionized, distilled or filtered water. Due to the size of the bottle and its opening, I advise holding the spray bottle a few inches away so only the mist gets in. It’s important not to let the moss dry out, or let it get saturated. Evenly damp is the key to healthy moss.
If you do overwater, use a pipette to remove any excess water.
I think this might be one of the smallest terrariums in the world!