Magnetic Frag Stations come in three sizes. Small, medium and large. Same features as our Frag Station but with a magnet added to them so they can be mounted to the side of the aquarium. These are sold by size and not hole count. Smalls will have four or more holes and in most cases will have room for additional coral frags not on plugs. Mediums will have up to ten holes and larges will have up to 20 holes. Sizes vary and no two are the same. Small and medium sizes are single shelved. Larges can be single or multi-shelved. They are solid ceramic and will not crumble or fall apart. It is very porous and in time will act similar to liverock. Frag Plugs are included.We utilize very strong magnets designed specifically for aquarium use. These are not the inexpensive hobby magnets you may find online. The Magnetic Frag Stations are recommended for aquariums with up to 1/2" glass or acrylic. We have tested them on 3/4" thick acrylic aquariums and they hold just fine. However you must use caution and load test every coral you place on theMagnetic Frag Station. We are not responsible for any damage caused by overloading the Magnetic Frag Station. Also extreme caution must be used when attatching the magnets to the aquarium. They can cause injuries and potentially damage the aquarium if allowed to snap together. We are not responsible for any damage or injury due to mishandling of the magnets.