Natural River Pebbles - Rounded pebbles - Creates a natural-looking riverbed - Easy to clean Exo Terra Turtle Pebbles are smooth river pebbles that have been naturally rounded over time in fast-flowing rivers. The smooth pebbles prevent injury to bottom-dwelling turtles or those searching for Food. The variety of colors and patterns creates a natural-looking riverbed. Exo Terra Small Turtle Pebbles (PT3830) are ideal for turtles with a shell diameter of 4 inches/10 cm or less. To prevent accidental ingestion in turtles with a shell diameter greater than 4 inches/10 cm, use Exo Terra Large Turtle Pebbles (PT3833). You can easily clean and reuse Exo Terra Turtle Pebbles by soaking and disinfecting them in a large bucket of water for 15 minutes, then rinsing until all visible particles are removed and the water is clear. Rounded pebbles (8-10 mm / 0.3 inch - 0.4 inch), safe for all turtles up to 4 inches or 10 cm.