A set of 5 glass capillary tubes that come with a stand. Place the stand in water, and fill a trough with water and place a capillary tube in it. The water will rise inside the tube, to a height above the water surface in the stand.
 Measurements:The outside diameter is 7 mm for each tubeThe inner diameters range from: 0.6 / 0.8 / 1 / 1.2 / 1.4mmTube height: 130mm