This scope offers the benefits of both multi-dot and multi-line scopes with a couple of new twists. Calibrated for crossbows that shoot in the 300 fps range, this 20, 30, and 40-yard combo crosshair and illuminated dot configuration is housed in a lightweight seven-inch aluminum tube equipped with fully-coated 3x optics. The illuminated dots are positioned at the intersection of each of the duplex crosshairs. In the field, you select non-illuminated black dots or one of two illuminated, colored dots (red or green) controlled by a five-position rheosat so you can match the illumination intensity to your hunting conditions. Recommend using Base Mount (Rail) # HCA-078 or HCA-072