Orion 5691 LaserMate Deluxe II Telescope Laser Collimator Want the best views possible from your reflector telescope? Perfectly align your reflector optics with our second-generation LaserMate Deluxe Collimator! Convenient rear view port lets you easily collimate optics from the rear of the reflector telescope Second-generation model features an improved aluminum housing with a wider, 3mm barrel flange to ensure proper seating for consistently pinpoint collimation with every use Operates on one CR2032 battery (included) and comes with a full set of instructions with a step-by-step procedure on how to properly align a relfecting telescope