Red Bull were the only team to opt for a very low-downforce set-up. In the drawing above we see the rear wing was even smaller than the one they used for the Russian race in Sochi. The main plane and flap have a shorter chord and a lower angle of incidence, whilst on the endplates the diagonal strakes have been removed - all reducing downforce and cutting drag.
It was a similar story with the front wing, as shown in the drawing above. For Spa, Red Bull brought back the experimental design tested briefly earlier this year in China, when it featured a serrated second flap (red arrow, left). Here it was reintroduced with a shorter chord to the final flap (red arrows) and minus the serration. Both Ricciardo and team mate Max Verstappen had this configuration for qualifying and race.