A left-arm vambrace; the bend would be placed at the knight's elbow
Vambraces (French: avant-bras, sometimes known as lower cannons in the Middle Ages) or forearm guards are tubular or gutter defences for the forearm worn as part of a suit of plate armour. Vambraces may be worn with or without separate couters in a full suit of medieval armour. The term originates in the early 14th century. They were made from either boiled leather or steel. Leather vambraces were sometimes reinforced with longitudinal strips of hardened hide or metal creating splinted armour.