Very good support to the discovery, simple and precise in his descriptions. The format is chosen, it fit in a large pocket pants like those side "carpenter", ideal for the ride. The plastic around offers effective protection. Very pleasant to browse, airy presentation with, for each tree, photos and drawings. The organization is clear, the classification procedure accessible to novices including myself, since based on the type (coniferous / deciduous / shrubs / vines) and then the shape of the leaves.