Muselet is a special metal cage that is placed over the cork to secure it. Before its invention, bottles were simply sealed with a cork and an oil-soaked sponge, then the whole assembly was sealed with wax. Winemakers quickly realized that this method was ineffective, as the wax cap would give way under pressure and the bottle would begin to leak. Soon after, iron muselets for champagne were introduced.

Since the creation of the first muselet in 1844, its design has undergone several significant changes. The latest version includes a steel wire twisted to increase the strength of the structure. A new feature is the addition of a small loop screwed into the bottom ring.

Champagne muselets often have a metal cap at the top of the structure. It serves a purely decorative function, but savvy marketers have used this space to place the logo or name of the winery, not only enhancing the look of the bottle but also serving as additional advertising.