The PSO series is the optic of choice for all Russian army cover or siege operations. Considered the higher end of military, side-mount scopes, the quality is a step up from other PSO-style scopes and is a much more effective for precision shooting. One look at the advanced reticle tells you everything! It has a magnesium alloy body and fully multicoated optics. A great assault weapon scope with an illuminated reticule grid, it allows you to determine kill distance as well as to track and observe game in the field. The variety of military reticles provide effective height-based rangefinding capabilities with graduated scales for both standing and prone figure estimation. Since the range calibrations are measured in equal amounts of MOA, all versions of the PSO can be used effectively with any caliber of weapon. The PSO features a red illuminated reticle which allows you to make perfect kill shots in dusk conditions. Illumination is provided by a simple diode; check our Accessories section for a variety of replacement diodes in various colors. The special design of the scope allows for both lateral and angular adjustments quickly and easily so you always stay zeroed in. It features professionally ground, crystal clear optics, nitrogen filling to prevent lens fogging, and larger diameter tubes for improved light gathering under the most severe conditions. It is waterproof and can be used in any climate condition. It comes with a high quality mil-spec finish, and with everything shown in the picture. If you want the look and performance of a true Red Army military optic and place a premium on shooting comfort, this is your best choice. The SVD/SKS clamp will fit any of these rifles with the standard side rail: SVD, SKS, NDM-96, Russian Tigr, Romak-3, SSG-97 and PSL rifles. The PSO series uses a standard AA battery.