The Vow of Friendship is a simple gold pocket watch with a clam-shaped clasp, and the Vongola Famiglia crest carved on the lid. When the watch is opened, the Guardian's respective Dying Will Flame burns on the middle of the clock. Givro eterna amicizia, lit. "I swear eternal friendship", is engraved on the underside of the lid.
In the manga, the lid of Daemon's pocket watch doesn't have the vow engraved as in the anime. Instead, a picture of Giotto and the other Guardians alongside Elena was placed. It is possible that the words might be covered by the photograph.
The pocket watches were given by Giotto himself and made by Talbot. It took three days for the pocket watches to be completed. When Giotto planned a secret dinner together for his Guardians, the watches were given to celebrate their friendship.
- Givro can also be spelled as Giuro, as "v" often stands for "u" in Latin or Ancient Italian.
- G mentioned that beneath the cover of each watch engraved a message and a number. Giotto said that the numbers are based from the name "Primo" that given by his guardians. What the message and the numbers are yet to be revealed.
- For some reason, all of the watches appear to be stopped at around 12:03 to 12:04.