TruGlo 30mm Traditional 1x Red Dot - 3-Dot - Crossbow Red-Dot sight. When shooting at close or medium ranges, a red dot sight is a great option for crossbow hunters. The 30MM TRADTIONAL offers unlimited eye-relief, a wide field of few, and a compact design that are not available in magnified optics. Descending Diameter Dots reticle for multi-distance shooting (smaller dot for longer shots) Unlimited eye relief Wide field of view Flip-up lens caps / lanyard system Lightweight compact design Easy to mount Integrated Weaver-style mounting system Battery included (TG988C, 3V-CR2032)