Jen with customer service was a tremendous help! I wanted the tunnels under the eaves & a bit away from the house - if house painting needed & to keep the kitties dry - then the tunnel extended out 90 degrees. Installation went smoothly!! I will be purchasing the Lion's Den next as I still need to create the foundation and this will connect to the tunnel. Three kitties venture in and out on their own and love it - as do I ... The 4th kitty hasn't mastered the cat door yet... Can't wait til the next phase!