McLaren tested their version of halo cockpit protection which has additional elements to boost its aerodynamic performance.
Halo will be introduced in Formula 1 2018 despite not being overally accepted because of its looks, additional weight and aerodynamic impact it has on the car.
Teams will have certain degree of freedom with their halo protection devices, including color and aero fairings which must be within the dimensions set by technical regulations.
McLaren is the first team to test additional elements on their halo device as they added three horizontal elements which mimic the shape of halo itself.
Three elements are structurally supported by small vertical support positioned in the middle.