Ocelot Zoom: Switch between the 25mm lens that offers a 1.3x base magnification and the 50mm lens that offers a 2.5x base magnification. You can view magnified HD images without distortion using the 2-8X digital zoom. Switch between the two lenses by adjusting the main lens ring back and forth and focus with the knob on the top of the ring. An important technical specification is the Noise Equivalent Temperature Difference (NETD) rating. This is one of the most important technical specifications for any thermal device. NETD indicates how small of a thermal difference the device can detect in the environment. The Ocelot Zoom is an industry leading a 20mK. The Ocelot Zoom features a cutting-edge uncooled Vanadium Oxide640x512 sensor that delivers clear images and crisp target details. It also features a 12Amicrom pixel pitch which is a measurement of the distance between the pixels of the digital image.25mm FOV: providing a wider field of view.50mm FoV: providing a long distance shooting game.