Feyachi Bore Sight .223 Rem 5.56mm NATO Red Laser Boresighter for Cal 223 556 with 3 Sets of Batteries

Features Adjust and zero-in your optic or iron sights without ever firing a round. High accuracy to reduce cartridges and shells wasted. Sturdy brass construction. Easy to sit perfectly in the bore.  Specification Construction: Brass Length: 44.5mm; Tail width: 9.5mm; Head width: 6.3mm Laser Wave length (nm:) 632 to 650 Power: <5 mW Sighting Range: 15 - 100 yards Dot Size: 2" at 100 yards Temperature: -10? to 40? Battery Type:6 x AG3 (Included)