This clock has been made from a Genuine North American P51-D Mustang Exhaust Stack. The stack was attached to a Packard Built Rolls Royce Merlin V-1650 Engine. The Unique Shape Of the stack produced extra thrust from the exhaust gases (albeit a minor Amount). Pioneer Aero Service has had this Stainless Steel Exhaust Stack Highly polished and mounted on a solid walnut base. A hand turned brass plug has been installed to mount the clock.