The Pro-40 is a zero-power 40 mm multi-dot scope with an integrated, adjustable 7/8-inch mounting system that requires no rings. Its three illuminated dots, calibrated for 20, 30, and 40-yards for crossbows that shoot in the 300 fps range, can be rendered in red or green to suit individual hunting and light conditions. The light intensity of both color views is regulated by a five-position rheostat.