These are quite a bit more sophisticated than the Mamods having proper chain driven steering and steam valve gear which presumably drives the piston in both directions. When I ran this engine it certainly seemed to go alright but at the time I did not have a large flat surface to run it on, it just went round and round in circles on the patio. It's got a geared drive system, which is an improvement on the Mamod belt drive, and a reverse gear. It's condition is good to excellent; there are no paint chips, except a few on the canopy, and the firebox is looking a bit stained. It has all its original accessories like oil, funnel and esbit fuel.