Suunto height meters quickly and accurately measure heights, especially of trees. They can also determine the angle of a gradient. Both clinometers and height meters have sturdy bodies made of corrosion-resistant anodized aluminium alloy. The scale cards run on special bearings in hermetically sealed plastic containers filled with a liquid which guarantees that they run freely and stop quickly. The liquid does not freeze or evaporate, retains full damping properties in all working conditions and eliminates irritating scale vibrations. For work in twilight conditions or even in total darkness, they can be supplied with built-in, maintenance-free light sources. PM-5/360 PC is the basic type. PM-5/1520 is for those who prefer the metric system. The instrument is equipped with two direct metric scales for use at distances of 15 and 20 meters.