[Stratoscope]

Mobile friendly:

> Every F‑TYPE is fitted with an Active Sports Exhaust that creates a race‑car inspired crescendo.

> The exhaust system reacts to throttle position, speed and engine revs by opening active valves. When open, these valves allow exhaust gases to take a more direct, less restrictive route through the rear silencer producing a much richer, more exhilarating sound. Where fitted, the Switchable Active Exhaust, allows you to manually open the exhaust valves so you can enjoy F‑TYPE’s stirring soundtrack at all engine speeds. This feature is optional on F‑TYPE and standard on all other models.

[cr0sh]

So essentially a muffler bypass valve? You can buy aftermarket valves like this from Summit Racing and JEGS - they aren't expensive, they come in a variety of styles (full manual where you have to unbolt them underneath the car, manual-actuated by a cable, electric actuated by a motor, and one company makes a "stealth" version).

Legality of use on public roads varies...