Although the in-house caliber B01 does not offer an 8-day power reserve, it does extend it by almost 3 days (70 hours) and is the most advanced available. This chronograph movement with column wheel control and the vertical clutch was launched in 2009 to mark the company’s 125th anniversary. Its basic version powers the Chronograph Mosquito, but a closer look reveals some subtle differences. For example, the eccentric screws used for fine adjustment are in different places and there are some finishing flaws on the lever used for the fake stopwatch function, which is unfortunately visible through the sapphire case-back.  
However, none of this seems to detract from Breitling’s excellent chronograph function. The B01 caliber operates with a very balanced rate result in various situations: on the chronograph, on the wrist, or when starting the chronograph is engaged. In this respect, the B01 movement is extremely reliable.
The vintage look is accentuated by the bright yellow color of the bottom of the leather strap. Under the sapphire case-back, the B01 movement is clearly visible.
It is housed in a 43 mm stainless steel case that, like the Navitimer, now has shorter, more curved lugs with polished edges that give the replica Rolex watch a more powerful and sporty look, especially when viewed from the side. From the 1930s to the 1960s, Breitling often completed its watches with these same facets.
Also inspired by history are the “mushroom-shaped” chronograph pushers, which, like the fluted crown, are another feature of the Navitimer. The column-wheel control gives the chronograph pushers a firm but very smooth point of force. The screw-down crown is difficult to release and hold in place but is easy to pull out to a different operating position.