Field Sport Cal .338 Lapua Laser Bore Sighter Boresighter, 338 Catridge Size, All Aluminum Red Anodized Finish, AG13 Battery and Long Battery Life Cal .338 Lapua Laser Bore Sighter Boresighter 338 Catridge Size All Aluminum Red Anodized Finish AG13 Battery and Long Battery Life Class IIIa 635nM Less Than 5mW