The overall battle for the Vuelta a España is heating up, with Primoš Roglic looking to snatch the red jersey from overall leader Ben O'Connor as the race enters the final stage.

O'Connor's once healthy lead has been whittled away in the last few stages, but Roglic will no doubt be looking for every advantage he can get to win. With the announcement this week that Dan Bigum will take over as technical director of Red Bull-Bohra-Hansgrohe, the pace may be even faster.

The quest for aero gains seems to have already begun, with Primosz Roglic using an unfamiliar computer on at least one stage of the race. In particular, on the dreaded climb of Cuitu Negru on stage 15, special attention seemed to be paid to Roglic, who switched to a lower gearing bike with a 1x drivetrain and a larger diameter cassette before the race hit the climb.

The Slovenian's mystery unit is clearly different from his other teammates who use the latest Hammerhead Karoo units, which were announced in May along with the SRAM Red AXS groupset. This computer is not dedicated to SRAM, but is designed for better integration with the Red AXS groupset.

Our thoughts on what this unit looks like are below, along with some useful pictures from the race that provide a clear comparison.

The Hammerhead Karoo is immediately recognizable thanks to its tapered shape and large white letters on the front of the unit. Currently, Roglic is the only Red Bull-Borla-Hansgrohe team to use an alternative computer, and it appears to be in use at several stages of the race. Although this unit is visible and hidden, it is considerably smaller than the team's stock unit and has no brand markings.

Details about this unit are unknown, and we can only speculate at this point; SRAM owns Hammerhead, and Karoo is designed to integrate with the Red AXS groupset that the team began using earlier this year.

We contacted SRAM and were told by the brand that the model in question is in fact a competitor's head unit, possibly a blacked out Garmin Edge 130 model. The brand says that it allows riders the flexibility to adapt to their specific needs on a particular day, and Roglič's use of a smaller alternative unit highlights its single-minded pursuit of the fastest possible setup while chasing victory.

Many WorldTour teams try to use the smallest computers possible in the name of aerodynamics. A small shape bolted to the front of a bike, no matter how small, saves aerodynamically. We found another example of this when we tested in the wind tunnel how aerodynamic it is to mount sunglasses on the front of the helmet. Along with a small computer, the team used a 3D-printed aerocomputer mount to smooth airflow in this area. We have posted several examples of these aero-computer mounts in the Vuelta's Tech Gallery.

We have already seen Garmin and Wahoo sponsored teams using the smaller Bolt and Edge 130 Plus models to gain a small aero advantage or to fit nicely between tri-bar extensions. Is there any possibility of a new smaller/race specific unit being developed from Hammerhead in the future?