Although an FA model was shown in the first brochures, this model was actually put into production, certainly some were made for evaluation purposes, but the first model you could actually purchase off the production line from Innocenti was this the FB.
The FB was launched just a few months after the two wheeled scooter, the Model B, the carrying section on these models was at the front, leaving the rear scooter section as normal therfore saving on production costs.
Three versions of box were offered on the FB, wooden box, aluminium compartment, or an open wooden box, all fitted with an exposed single headlight at the front which could be easily broken while parking. The front wheels of the FB turned, while the carring compartment stayed straight using a parallelogram shaped system similar to cars of the day.
The 125cc engine toped out at a maximum speed of just over 30mph (45kmh) and could cope with loads of up to 200kg, while ideal load carrying over distances, the small "van" was just enough around town,
To improve engine cooling, an air duct was mounted above the flywheel which sent air to the cylinder via an aluminum spiraled vent. All three drum brakes were operated by a single brake pedal, equiped with a gear to compensate for the three wheels, making the brakes operate on all three wheels at the same time.
Even though the price was well below any competition Innocenti had with this three wheeler, and reliabilty had already got a good name from the A series of scooter, after just under a year of production only 2,000 units had been sold, less then Lambretta had hoped for.