Type II sights are low-power magnified optics with reticle features providing aiming points for distant targets. The Type II optic should not have external knobs to prevent loss of zero due to the knobs being bumped. They are optimized for 75 to about 400 yards. Type II optics are generally either fixed magnification in the three to four power range, or are variable power in the one to four range. The most common Type II optic is the Trijicon ACOG, in either the 4x versions (TA31, TA01) or the 3.5x version (TA11). The US Military realizes these capabilities in the Designated Marksman Rifle (DMR) and Squad Designated Marksman Rifle (SDM-R).
At very close range, Type II optics are much slower to acquire a sight picture than the Type I red dots. They can be stretched to 600 to 800 yards provided the target is large and the reticle provides sufficient bullet-drop compensation (BDC) features. These optics provide good target spotting and identification. Close-range speed can be improved by the addition of a brightly illuminated reticle center, since the brain is drawn quickly to bright objects. The TA31 and TA11 ACOGs have this feature, as does the Schmidt and Bender Short Dot.
Low-power variable-magnification Type II optics improve close-range target acquisition speed at their lowest magnification setting; the closer to true 1x the better. The goal of these variable-power scopes is to provide the speed of the Type I optic, but still the target ID and distance capabilities of the Type II optics. The price for this flexibility is paid in increased purchase cost, less durability, and more weight and bulk on the carbine.