The biOrb Slate Stack Ornament is a strong angular piece. Mix with plenty of topiary and colourfulplants for a bold display. Simply slide over the bubble tube in the biOrb.Hand crafted design from aquatics dcor designer Samuel Baker. Made from durable high grade resin that wont fade. Easily slides over the biOrb bubble tube for easy placement. Compatible with Freshwater/Saltwater/Tropical aquarium set ups.It is easy to fit and remove. The larger and is 8.27 inches / 21 cm tall.