Medium standard Base Rock IslandThis base island measures 9"x7"x3. 5" high. It features coralline algae look with a grayish rock color. There are multiple holes drilled in this base for easy insertion of plug on corals. All of our corals come pre drilled with a plastic threaded peg for plugging onto the bases. You can use a 3 8" drill bit to drill as many more holes in the rock base as you would like! Enjoy!!