What is the Brown Scapular?

The Scapular of Our Lady of Mt. Carmel, or Brown Scapular, consists of two pieces of brown wool on a cord. The Blessed Mother gave this sacramental to St. Simon Stock in 1251 with the promise that “Whoever dies invested with this Scapular shall be preserved from the eternal flames. It is a sign of salvation, a sure safeguard in danger, a pledge of peace and of my special protection until the end of the ages.”

According to the Holy See’s Directory on Popular Piety,

205. The history of Marian piety also includes “devotion” to various Scapulars, the most common of which is devotion to the Scapular of Our Lady of Mount Carmel. Its use is truly universal and, undoubtedly, it is one of those pious practices which the Council described as “recommended by the Magisterium throughout the centuries” (Second Vatican Council, Lumen Gentium, Chapter VIII).
The Scapular of Mount Carmel is a reduced form of the religious habit of the Order of the Friars of the Blessed Virgin of Mount Carmel. Its use is very diffuse and often independent of the life and spirituality of the Carmelite family.

As a small version of the Scapular of the Carmelite Order, those who wear it practicing virtue associate themselves with the Carmelite Order, both in their devotion to the Blessed Virgin Mary, and their expectation of her protection.