The Broad Stair (also called the Brown Stair) is an iconic piece of Montessori Sensorial material designed to help students develop their ability to recognize differences in size, both visually and through their sense of touch. The set consists of ten solid wood blocks each 20 cm long in sizes from 1 cm to 10 cm. The blocks have a solid dark brown painted finish with a scratch and chip-resistant clear coat. The Broad Stair set includes one extra 1 cm prism (two in total), and can be used together with the Thin Prisms (sold separately) to expand the number of possible exercises. Colour may not be exactly as shown.