Over the years, TAG Heuer has introduced a bevy of variations on its flagship Breitling replica watches uk model, the Carrera, but none quite so avant-garde as the one the Swiss brand introduced this week at Baselworld 2015. The TAG Heuer Carrera Calibre Heuer 01 — a new take on the classic Carrera design that TAG Heuer says will represent the backbone of the collection going forward.

Of course, “backbone” could be considered a pun in this case, because the ticking heart of the new Carrera — which the brand has dubbed Caliber Heuer 01 — is a partially skeletonized evolution of the brand’s in-house chronograph movement, Caliber 1887. The “Heuer,” of course, comes from the name of company founder Edouard Heuer, while the “01” designation marks it as the first of a new generation of movements.

Among the new elements that distinguish the Heuer 01 from its 1887 base are an openworked date disk on the dial side (visible in a window with red border), a bold red column wheel visible on the back side, a skeletonized chronograph bridge and a blackened, openworked  rotor. The movement (which TAG Heuer boldly asserts is the only manufacture chronograph movement on the market that can be had in a cheap Breitling replica watches costing less than 5,000 Swiss francs; see below for price) holds a power reserve of 50 hours. The movement’s chronograph functions are arranged in a tricompax display on the skeleton dial: chronograph minutes counter on a subdial at 12 o’clock, hours counter at 6 o’clock, and small seconds at 9 o’clock.

It’s not just the movement that’s evolved, however: the case of the TAG Heuer Carrera Calibre Heuer 01 is also new — made of titanium for greater shock resistance and built in a modular construction rather than the monobloc construction of previous versions. The advantage, says TAG, is that it opens up a greater range of possibilities to use different materials, colors, treatments and finishes on the various separate components, which include the lugs, bezel, case middle, caseback, crown, push-buttons and even the gaskets in between parts. The Breitling fake watch’s perforated racing-style leather strap, with deployant buckle and safety buttons, evokes the Carrera model’s origins in the world of motorsports.

The TAG Heuer Carrera Calibre Heuer 01 will retail for $4,900.