A devotional scapular typically consists of two small (usually rectangular) pieces of cloth, wood or laminated paper, a few inches in size, which may bear religious images or text, joined by two strings and worn so that the cloths rest on the sternum and the back. They evolved from monastic scapulars, parts of monastic habits which are lengths of cloth suspended both front and back from the shoulders of the wearer, often reaching to the knees. Devotees wear devotional scapulars to denote piety and to receive the associated indulgences and/or privileges. Since 1910, people have been permitted a single metal scapular medal in place of multiple cloth scapulars.

Sources:

Congregation for the Doctrine of the Faith, "The Scapular Medal," trans. EWTN Global Catholic Network. Accessed 22 October 2024. https://www.ewtn.com/catholicism/library/scapular-medal-2105.

Hilgers, Joseph. "Scapular." In The Catholic Encyclopedia. Robert Appleton Company, 1912. http://www.newadvent.org/cathen/13508b.htm.

"Scapular," Wikipedia, September 30, 2024. https://en.wikipedia.org/wiki/Scapular.