Seachem Coral Frag Plugs are specially designed with qualities. This plug resembles a small one legged table. The peg in the bottom is designed to fit nicely into eggcrate, it will also fit nicely into a small crevice or holes in your live rock as future resting places for our frag plugs and it also looks more natural then aragocrete. Reef Plugs are designed to support Acropora, Montipora Digitata and other thin branchy species of coral.