The Pressure Cylinders provide experiences in pairing and grading degrees of pressure. By pressing the spring-loaded plungers, the child senses the difference in resistance pressure. The set includes a wooden tray that holds 6 matching pairs of pressure cylinders. Designed by George Russell. This set helps to develop the ability to discriminate varying degrees of pressure. By pressing the spring loaded plungers, children sense and match the pressure. Set includes 6 pairs of cylinders in varying degrees of pressure. Trace around the base of the cylinder using the index and middle fingers. Using these same finger, trace around the matching hole on the wooden block. Place the cylinder in the correct hole slowly, allowing the child to follow your movements. Repeat with the other cylinders.