This tunnel was originally a 121" and it was modified to be 144". The rear end of the tunnel has the extending plate welded on. Does have some grind marks from disassembly. The plate can easily be grounded off if you want to make it a 121" again. If going to run as a 144" it will have to be welded to the foot panels. Heat exchanger has no damage. Has normal wear from use. Comes complete as show in pictures.