The ATN PS22-2I is an attachment for the Daytime Riflescope with 1x-6x (2.5x-4x are optimal) magnification that is converting the Scope into a high-quality, very accurate Night Vision Weapon Sight . The ATN PS22-2I mounts in front of a Daytime Scope. Re-zeroing of the Scope is not required. The ATN PS22-2I comes standard with 7/8" Weaver Mount. There is also Adapter for ARMS quick release mount. Optional Ring Adapters allows to mount the unit onto the objective of the Daytime Scope (25...62mm diameter). The IR Illuminator can be mounted onto the optional Picatinny Rail. The ATN PS22-2I System utilizes a 2nd+ Gen. or 3rd Gen. Image Intensifier Tube. This ingenious setup allows the shooter to go from day to night in less than 30 seconds without tools, without changes in eye relief and remain zeroed all around the clock.  The ATN PS22-2I is a complex optical-electronic system. The Night Vision Device contains an Image Intensifier Tube assembly with an integrated high-voltage power source and the three volt battery housing.