Ideal for hilly or mountainous terrain. Accurate to 1% of rated BAF. Efficient familiar design (30 ellipse curvature at top) for all general cruising. Base is parallel to horizontal axis for slope correction reference. Clear glass prisms perform satisfactorily in most cruising conditions. Amber glass prisms prove superior when cruising is done in low light, hazy or misty conditions. 40 mm x 40 mm. Leather case included.Forestry Suppliers, Inc.