Pirelli announces the following compounds for the third and fourth rounds of the 2017 Formula 1 season.

In BAHRAIN*, to be held from April 14-16 on the Sakhir circuit:

• P Zero White medium
• P Zero Yellow soft
• P Zero Red supersoft

These are the tyres that must be available (at least one of them to be used) at some point in the race:

• One set of P Zero White medium
• One set of P Zero Yellow soft

There are the tyres assigned for Q3 in qualifying:

• One set of P Zero Red supersoft

In RUSSIA*, to be held from April 28-30 on the Sochi circuit:

• P Zero Yellow soft
• P Zero Red supersoft
• P Zero Purple ultrasoft

These are the tyres that must be available (at least one of them to be used) at some point in the race:

• One set of P Zero Yellow soft
• One set of P Zero Red supersoft

There are the tyres assigned for Q3 in qualifying:

• One set of P Zero Purple ultrasoft

*The tyre nomination for long-haul events has to be made 15 weeks in advance, whereas for European races the deadline is nine weeks in advance.

In accordance with the regulations, each driver must save for Q3 one set of the softest of the three nominated compounds. This set will be given back to Pirelli after Q3 for those who qualify in the top 10, but the remaining drivers will keep it for the race.

For the first five events of the season all 13 sets for each driver are identical and defined in the regulations: seven sets of the softest of the three nominated compounds, four sets of the middle compound and two of the hardest compound nominated.

ABOUT THE 2017 TYRES:

•   The range has been completely transformed, with new sizes (305/670-13 at the front and 405/670-13 at the rear) as well as new profiles, constructions and compounds.

•   The compounds in particular make use of entirely new materials and a completely fresh design philosophy.

•   After a very positive testing programme with the new sizes Pirelli has decided to additionally homologate a back-up compound alongside each of the five new base compounds. These extra compounds are formulated using more traditional criteria compared to the new base compounds.

•   For the first part of the championship, only the new-generation base compounds have been selected.

•   The back-up compounds could be introduced later in the season to respond to any particular requirements once the real performance levels of the 2017 cars have been identified.