Secure the display and IR light on the optical sight with the pipe clamp. Loosen screws , and centrally fix the connecting tube in the rear of the eyepiece of the optical sight. Turn on the machine and rotate the lens of the machine (inside the tube) to adjust the focus, and adjust the cross line of optical sight to be clear. Adjust the position of the connecting tube, and tighten the screws till the cross line in the center of the display. Do not move the machine lens, otherwise the cross line will be blurry. The item "NIGHTPAL 200 MM DIGITAL NIGHT VISION SCOPE SYSTEM" is in sale since Tuesday, November 26, 2019. This item is in the category "Sporting Goods\Hunting\Scopes, Optics & Lasers\Other Hunting Scopes & Optics". The seller is "nightpaltactics" and is located in San Francisco, California. This item can be shipped to United States.