Montessori Brown Stair with Control Cards - Sensorial MaterialProduct Description The Montessori Brown Stair with Control Cards is a classic Sensorial material used to develop a childs visual discrimination of width. This set includes ten brown wooden prisms, each equal in length but varying in thickness from 1 cm to 10 cm, providing concrete experience with the concept of gradation. Also included are matching control cards to support visual matching, sequencing, and independent correctionreinforcing Montessori