Team Sky riders will continue to wear Kask helmets through to the end of the 2020 season.
The British WorldTour squad has used the Italian brand since its inception in 2010, and on Wednesday announced a four-year extension to the partnership.
"Having worked directly with Kask for the last eight years it was an easy decision to continue that collaboration," said Carsten Jeppesen, Team Sky's head of technical operations.
"Our riders and technicians demand and expect the best in terms of protection, comfort, and performance, whatever they face in races and training. We need continued innovation and development from our helmet supplier to ensure we stay ahead of the pack in every way we can. That's what we expect, and that's what we get from Kask."
The first model of helmet used by Sky was the Vertigo, and in 2012 the Mojito came along, with its 'marginal gain' of antibacterial and antimicrobial padding. The Infinity features vents that can be opened and closed depending on whether the rider wants comfort or aerodynamics, while many riders now use the lightweight Protone.
For time trialling, the riders use the Bambino model, recently upgraded to the Bambino Pro Evo TT, which 'combines long-tail aero benefits with short-tail robustness'.
Kask say they will be collaborating with the team to produce new models in the future.
"Team Sky entrusting the safety of their riders to us, as helmet supplier, is both a big honour and big responsibility, and one that we strive hard year on year to both match and exceed," said Kask's general manager, Diego Zambon.
"At Kask we always keep the pressure on our programme of research and development to create new designs with opportunities for performance improvement. It's a fantastic challenge to provide this service to an outfit of the calibre of Team Sky for another four years."
Team Sky are changing kit supplier from 2017, switching from Rapha to Castelli.