This could be one of the weirder issues with 2019 equipment. Some drivers will be without 2019 spec helmets after three of the four helmet suppliers for F1 have failed to meet the standards for all sizes.
New rules have meant that helmets for 2019 must be stronger than before, reducing the chance of head injuries to drivers, but only Stilo have met all the requirements to reach homologation.
Schuberth only has its medium sized helmets homologated, whilst Bell, who will supply as many as ten drivers, only has sizes from 56+.
The most worrying supplier is Arai, who will not receive approval from the FIA before pre-season testing, meaning none of their customers will use the new spec helmets.
Arai’s customers include Sebastian Vettel, Max Verstappen, Pierre Gasly and Daniel Ricciardo, so some of the drivers who could be in contention for podium positions at the opening few races will not have as long to get used to their new lids.
A statement from Arai read: "The prototype of the new model has been supplied.
"It is not yet officially homologated, but our in-house tests assure the product quality."