Akrapovic Exhaust Sound Kit - 981 | Boxster | CaymanAkrapovic Exhaust Sound Kit 20142024 Porsche 981 Boxster Cayman Part #: P HF964 Overview The Akrapovic Exhaust Sound Kit is an innovative accessory designed for owners of select Akrapovic exhaust systems on the Porsche 981 Boxster and Cayman models. This advanced sound control system allows you to customize the auditory experience of your vehicle, providing the flexibility to switch between a quiet, refined tone and a more aggressive, sporty sound at