Gas pressurized spring, hood

Rolls-Royce part number 51237040711 is a gas-pressurized spring hood, also known as a bonnet gas strut or hood lift support. It is a gas-filled cylinder that is used to assist in the opening and closing of the car's hood.
The gas spring is attached to the hood and the frame of the car. When the hood is closed, the gas spring is compressed. When the hood is opened, the gas spring expands, providing assistance to the user in lifting the hood.