This is a refill boom and cannula for your existing Aithre boom cannula.
The Aithre boom cannula initially comes with a boom, cannula, and an anodized aluminum adapter that is designed to last just as long as your headset. And, while the boom and cannula pieces will last a long time too, most aviators like to occasionally get replacements for these consumable parts.
This replacement boom and cannula is easily installed on your existing Aithre boom cannula without any tools. Simply pull the old boom and cannula off the anodized aluminum adapter, and push the new cannula and boom onto the adapter. This exchange keeps your Aithre boom cannula fresh, sanitary, and retaining that like-new feel for years to come.