The Sentinel 2.5x50 26015T combines traditional Yukon style (perfect design, ergonomics, reliability and easy and convenient use) with an enhanced level of functionality. The Sentinel has a high grade of water resistance (IPX4 grade, according to the standard IEC 60529) and can be operated in precipitation of high intensity. Extra tube protection provides durability towards axial load when used with the majority of popular calibers, including .300, .308 or similar. The batteries (2xAA) are placed in the battery compartment vertically thus eliminating the influence of recoil on the stability of the energy supply. The Sentinel has two scales - a horizontal scale to measure distance to the target, and a vertical one which facilitates adjustment when shooting at different distances. Initially the riflescope should be sighted at 50m. on the central cross hair. The distance is determined by putting a target with known width (0.5m) between the marks of the “>..<” type. If the target fits between the marks, you sho uld make the vertical adjustment according to the mark. So, you can make adjustments when shooting at distances of 15, 25, 50 and 100m. It is advisable to change the color of the reticle depending on the surrounding conditions. Red is best when used in clear viewing conditions, green is preferable for use when viewing is obscured. The color can be changed by a simple push of a button. The image focusing mechanism (from 2 m. up to infinity) with fixation of the focus ring knob at the mark “100m”, provides clear image at any distances (including short) within the riflescope's working range. Double function LED indicator. Green light when the battery is full. As the battery runs down, the power indicator changes its color from green to red. This means that the riflescope will still be functioning for about half an hour before the battery is completely empty. Along with standard functions, the remote control has a quick start-up function. This is very convenient when constant observation is not conducted in order to find the appropriate position, take aim and shoot. A stabilized power supply ensures up to 70 hours of full operation. This prevents reticle shift, change of its brightness even when the battery is nearly empty. The built-in IR illuminator makes it possible to use the riflescope in utter darkness. The IR has the function of focusing the light flux, ranging from narrow directed to dispersed. The riflescope has an extra 7/8” Weaver rail placed on the left side of the body and is designed for mounting accessories (IR illuminator, directional microphone and laser pointer). A soft rubber cap is permanently fixed on the riflescope’s housing to secure it from being lost. When using the riflescope, there is no need to remove the cap, it can simply be placed on the riflescope’s body in the most suitable position. The Sentinel can be supplied with one of the five types of mounts, including Weaver mount (Weaver-Auto, Weaver-Long), AK Side Mount, "Los" mount (for Russian rifles), Prism 14/200 mount. SPECIFICATIONS Image intensifier tube classification Gen 1 Magnification, x 2.5 Lens diameter, mm 50 Field of view, degree 15° Resolution (typical), lp/mm 32−36 Focus range, yard 1 to infinity Eye relief, mm 45 Diopter adjustment, dptr +/- 4 Detection range, yard up to 230 Recognition range, yard up to 120 IR illuminator effective distance, yard up to 100 Reticle type Illuminated Red-on-Green duplex Reticle windage/elevation adjustment ½ MOA per click Power supply 3V (two AA) Estimated battery life (w/out IR), hour up to 50 Operating temperature, °F -22° to +122° Dimensions, in 10.0" x 3.1" x 3.3" Weight, oz 33.5 Included Accessories: “On-Rifle” carrying case Adapter for 35mm cameras Remote On/Off switch Optional Accessories: NVRS Magnification Doubler 2.5x50 to 4.3x50 (#29091) NVMT / NVRS IR Flashlight (#29074) Directional Sound Amplification System (#27022) AK Side Mount to Weaver Adapter (#29044) Digital Camera Adapter (#29023) Tactical Waterproof Case (#29087)