Fernando Alonso and Lewis Hamilton will become the latest drivers to test the Halo at the Singapore Grand Prix, their teams have confirmed.
F1's teams have been continuing trials of the cockpit protection system over recent races, despite the Strategy Group having voted to delay the introduction of the concept until 2018 at the earliest.
Mercedes, Ferrari, Red Bull and Force India have all tested the Halo at recent races, with several drivers getting their first taste of it.
Now, McLaren and Mercedes have revealed that former champions Alonso and Hamilton will run the Halo during Friday free practice at Singapore in a fortnight's time.
McLaren technical director Tim Goss said: "Testing the device through the year with all the teams has already been very instructive. For McLaren, running with Jenson [Button] at Monza has allowed us to gain insight into its performance in both tight chicanes and high-speed corners.
"The plan is for Fernando to try it in Singapore, which will offer up a number of different variables: the circuit is lit, with some very tight corners, and with plenty of Armco barriers.
"His thoughts will be fed back into the working group as the teams progress with the ongoing development of head protection alternatives."