These little Bolbitus plugs with moss are perfect for smaller aquariums (or hardscapes) where you want a plant in a certain area. They've been tied onto lava rock which means you can move them around so if you don't like where you've put them to begin with, you can simply move them. Easy as that.
If you wanted to place them in your existing hardscape, you pop them into the area you think they'll look best - as they're already tied on it means there's no further work for you and there's no fiddling around.
Summary: These little plugs are very user friendly - easy to grow with no work needed from you. Simply pop them where you like and wait for them to grow.
Lava rock ranges in size but typically 4-6cm long - we try and choose proportional sizes according to the plant dimensions.