F-Attachment

Many professional level trombones will feature a rotor mechanism called an F-attachment. This lowers the trombone’s pitch by a perfect fourth, allowing the player to achieve lower notes with easier slide positions. F-attachments come in two types often referred to as closed wrap and open or traditional wrap. The difference between the two is the profile of the tubing with open taking more space than closed, while closed may have more playing resistance. The benefits of either type are up to player preference.

One Piece Bell

On instruments of a higher make or quality you will often see the term one piece bell. This means that the bell section will vibrate more evenly and without interruption. This a more nuanced component for the more advanced player, most student level instruments are constructed with two piece bell sections.