The Formula One launch season continued on Tuesday as Sauber unveiled their first car following its new partnership with Alfa Romeo.
Italian manufacturer Alfa Romeo is back in the sport following an absence of more than three decades and its white and red colour scheme has been adopted by Sauber.
Sauber, who will be powered by Ferrari engines this season, finished last in the 2017 constructors' championship after scoring only five points.
The heavily-sponsored Swedish driver Marcus Ericsson has been retained by the Swiss team, while Charles Leclerc, the impressive young Frenchman who won F1's feeder series Formula Two last year, joins as a rookie.
Sauber boss Frederic Vasseur said: "I am convinced that Marcus and Charles form the perfect driver line-up, with one being an experienced driver and one a promising rookie.
"Our target ahead of 2018 is clear. We have to catch up with the field and continue improving our performance during the course of the season."
Sauber's launch follows Haas, Williams and Red Bull, with Renault due to take the wraps off their new car later on Tuesday.
Four-time world champion Lewis Hamilton will be at Silverstone on Thursday for Mercedes' car launch.