It doesn't get any better then our 8-24x75 for Target and Varmint shooting. An amazing 75mm objective lens provides the user with the brightest image available in a daytime scope. Includes 6 interchangeable cams (Caliber's .22-250, .308, 30-. 06, .243 Win, 7 mm Mag, .300 Win Mag, .50 BMG) and 1 set of 30mm steel rings. The 8-24x75 is the Ultimate Varmint/Target scope.... The 8-24x75 has an Electronic reticle. There are 10 degrees of illumination. The rheostat is the knob located at the back of the scope. It is labeled with numbers 0 through 10. When the rheostat is set at 0 you will see a black etched reticle. The reticle will light up red electronically as you rotate the rheostat through the numbers, 10 being the brightest..... The rangefinder reticle in 8-24x75 was designed to assist you in determining the range of your target. These distances are based on a 6' target, if a 6' target fits between the numbered baseline (the ten short horizontal lines) and the post of the reticle above the baseline determines your distance. If a 6' target fits between the horizontal post of the reticle and 2 the target is 200 yards away. If the same target fits between the 4 and the horizontal post of the reticle the target is 400 yards away. The same is with the 6, 8, 10, 12, 14, 16, 18 and 20. The target would be either 600, 800, 1000, 1200, 1400, 1600, 1800 or 2000 yards away... The tube is made of aluminum-titan alloy. Thickness 1.5-2.0 mm. Nitrogen filled inside. No air. The glass lens is installed in hard rubber rings, no moisture or fogging. LifeTime Limited Warranty 100 % parts and labor from ATN !