The most popular scapular we know of, is that of Our Lady of Mount Carmel, or the “Brown Scapular.” Wearing the Brown Scapular expresses devotion to the Mother of God, trust in her intercession, submission to her spiritual maternity, and a desire to emulate her faithfulness. In return, wearers may hope, in faith, to receive the privileges and promises associated with the wearing of the scapular.
A scapular does not offer magical protection. But it can be spiritually powerful, due to the blessings bestowed on it through the Church’s intercession. Wearing a blessed scapular indicates, first and foremost, the conscious effort of one who is motivated to live as a true disciple of Christ. In this way, a scapular offers many occasions of grace. It acts as a reminder to pray regularly, to ask the intercession of the Blessed Mother, and to live a faith-filled life.
Source: Catholic Digest