Ready Landforms are durable and realistically landscaped. Ready to set in place, they blend with any layout and work for any number of projects. They easily stack for space-saving storage and portability, and they are ideal for war gaming and traveling layouts. Tunnels and Rocky Ridges are perfect complements to ReadyGrass® Vinyl Mats16 1/2” w x 10” d x 5” h, (portal opening 1 3/8” w x 1 3/4” h) This tunnel is designed for an 11" radius, but also allows for 9¾"-19" radii.