This is our 1 hole mini Frag plug rock base by Ocean Aquaria!! Made in the United States, we use a special polymer resin filled with calcium carbonate that makes it very durable and weighted enough to be very stable in the sand!! This frag rock base offers 4 color options to enhance the look of your aquarium (of course we can make it in any color by request ). It also provides a natural and stable environment for live coral and other aquatic organisms, promoting healthy growth and filtration in your tank. Designed specially for Reef Tank enthusiasts looking to update and "bling out" their aquascape!! measures 3"x2.5"x1.5"