Knobbed socket cylinder . 1. Develop child's coordination of movement. 2. Strengthen child's pincer grasp. 3. Develop child's visual perception of dimension. . Content: blocks with 5 cylinders each. or 1 set ( 4 blocks) Material: Solid wood. Packing 1 set: 16 x 17 x 6 cm, White box @15x4x6 cm . Age 1+