1.8m W x 1.8m D @ 200/400/600mm High, Tread is 600mm deep. Rise is 200mm Each Choir Riser can hold 5 children per row and 3 adults per row. Gas arm assisted wings. Black low pile carpet. On castors for easy manoeuvrability. One person can set up and pack down. TSC recommends handrails along rear and sides.