F1 drivers are waiting to have their new helmets approved for use in 2019.
Last year, the FIA announced that a mandatory new standard for 2019 called FIA 8860 would have ballistic protection and a smaller visor opening.
F1's governing body said it worked closely on the new regulations with Stilo, Bell, Schuberth and Arai.
"It is now up to these manufacturers to deliver the production versions of the new helmets for 2019," the FIA declared.
However, Brazil's Globo reports that not all the manufacturers have had their 2019 helmets approved -- even though winter testing begins in mere days.
The Japanese manufacturer Arai is among the manufactures yet to have the 2019 helmet approved. Sebastian Vettel, Max Verstappen and Daniel Ricciardo are among the drivers who use Arai helmets.
Stilo, supplier to Lance Stroll and Valtteri Bottas, does have an approved 2019 helmet design.
Arai said in a statement: "The prototype of the new model has been supplied. It is not yet officially approved, but our internal tests guarantee the quality of the product."
