Sebastian Vettel says the second-generation Formula 1 halo cockpit protection device needs further running after raising concerns over visibility in certain areas.

The German completed an installation lap on Friday with the device, which features a central pillar and is dubbed “halo 2,” after revisions were made following on-track tests at Barcelona in pre-season. The latest version is made of titanium, which makes it lighter but just as robust.

When asked for his thoughts on visibility, Vettel said: “Forward visibility was fine because it was just an installation lap, the first run of the day. Full visibility was OK – obviously you still have something in the middle [the pillar], but you lose quite a bit on top of you. You’re not looking in the sky when you drive around but it needs some further running.”

Further improvements are expected and it is anticipated the FIA will give the final design the green light before the summer break later this month.

“It is clear what it is made for and it’s clear what it is supposed to do, we just need to make sure we introduce something that is safer in all circumstances and we don’t make any compromises,” added Vettel. “You will always have certain scenarios which you can’t cover. But you try to cover as many as possible, so that has to be the target.”