This interesting engine is simple but well built with sturdy materials. It is unusual in having the boiler and engine enclosed in an "engine house".
The boiler is quite small at 50mm diameter x 80mm length and 80ml water capacity, fired by a burner holding two Esbit tablets. It has no water level indication and the only fitting is a safety valve.
Steam is fed via a pipe which exits the boiler at the bottom, presumably with the end at the top, although there is no visible steam dome. There are no throttle, lubricator or superheater and the pipe goes directly to the rear of the engine frame.
The engine is a single cylinder single acting oscillating cylinder, vertically mounted below the crankshaft. Cylinder dimensions are (approx) 8mm bore x 20mm stroke (access is difficult to measure accurately). The crankshaft has one bearing in the engine frame and the other in the outer casing. There is a combined flywheel and drive pulley outside the housing.
Exhaust steam is fed to the chimney. Because of the enclosed nature, much of the hot gasses from the burner will also go up the chimney, although much will also escape through the hole on the side next to the cylinder.