The BfB Baroque™ is really two trumpets in one:
First, it is a vented trumpet that plays in standard Baroque keys at modern (A=440) or Baroque (A=415) pitch.
Second, it is a natural trumpet that can be crooked up or down to the keys necessary for playing Classical period music from the eighteenth and nineteenth centuries in modern pitch (A=440).
The dual-nature of the BfB Baroque™ is possible because of its short profile. Since crook sets are changed in both the front and back of the instrument, the vents stay in the middle of the trumpet, allowing for a wide range of keys that can be offered with vented yards. Additionally, many players will find it possible to hand-stop* the instrument, allowing it to be played like an "invention trumpet" of the late eighteenth/early nineteenth centuries.
The BfB Baroque™ is a great stepping-stone instrument for entering the world of period performance. Trumpeters learning the natural trumpet will enjoy numerous pedagogical benefits which can bring new skills and meaning to playing the modern trumpet.
*Hand-stopping on the BfB Baroque™ is only possible if your arms are long enough to stop notes on a standard Bb trumpet.