Use vertical ring tree to increase ROM, eye-hand coordination, manipulation, endurance and sequencing. Base: measures 21-3/4" x 14-1/2" x 1-1/2" deep. Set includes 6 plastic rods: 3 are 18" high and 3 are 13" high. The diameters of rods vary between 1/4" and 1". Set includes 12 rings for each rod.