Designed to aid in the protection of either a baby anemone, mushroom , or leather coral. Will allow a mushroom or leather coral to naturally attach to a plug, disk or rubble. Prevents your mushroom from being pulled away by the currents within your tank and accidentally sucked away by either your overflow or filtration system. Size - Fits up to a 3" Inch Frag disk or plug. These are 3D Printed from Reef Safe PETG Plastics. Each shroom Box has a matching locking lid, just align the grooves, and the lid snaps securely into place. Custom made plugs or discs to match are available and sold separately.