Tunnel with straight access. A cedar floor is included with each tunnel. Tunnels are the perfect component for securely connecting Habitat Haven components. The openings in stairs, towers, bridges, and enclosures all accept tunnels. So, this makes it a flexible way to span between components or between buildings and the enclosure! A cedar floor is included with each tunnel. Tunnels are 12"W x 15"H x your chosen length. Tunnels will arrive fully assembled with access points/openings based on the configuration you choose. Tunnels are available in 2-inch length increments from 2" to 92." Keep in mind that tunnels can be connected together to make longer sections than 92." We recommend support approximately every 10-12 feet (either attached to a structure or a support post) but they can be used in longer spans with the understanding there may incrementally more flex and sway the longer you span.