This Larger 8" x 11" (20.3 x 27.9 cm) Model is perfect for Instructional Uses. Slate has Plenty of Room for Note Taking, Communications, Skill Performance or just Conversing Underwater. Slate comes with a Pencil on Rubber Lanyard to prevent you from losing it, also Pencil Clip to secure Pencil to the Slate. The Slate is also equipped with a Split Ring with 360 Swivel Non-Corrosive Plastic Gate Clip to attach to a Lanyard for Ease-of-Use. Instructional people are always taking notes on a dive, so the Large-Format is ideal for their use. Slate is made from Durable Plastic and is Easily Erasable.