1PN58 (Russian: 1ПН58) is the GRAU index for a Soviet designed passive night scope for a range of Soviet designed small arms and grenade launchers. 1PN is the GRAU index of night vision devices, where PN stands for Nochnoy Pritsel (Russian: Ночной прицел) meaning night sight. It is also called NSPUM (Russian: НСПУМ).
The scope weighs 2 kg and measures 458 mm × 186 mm × 99 mm (length × height × width).
It is attached onto a matching side rail on the weapon after which a lever on the scope is pressed to hold it in place.
The 1PN58 comes in a metal container with room for extra batteries, battery charger and the other accessories, weighing 7.3 kg in total.
The scope gathers light into a refractor which can be protected with an aperture cover. The center of the cover has a circular aperture with dark glass allowing the scope to be used in light conditions that would otherwise saturate the light intensifier.
For zeroing the sight the left side of the scope has two perpendicular knobs, of which the elevation knob has a detachable scale. The scope comes with seven different, detachable elevation scales, one for each of the supported weapons.
The eyepiece has a detachable soft rubber eyecup.
The scope has a magnification of 3.5.
On the left below the aperture the device has a brightness knob. Apart from powering on and off the device, this knob controls the brightness of the reticle allowing for the reticle to be visible without outshining the target.
The reticle has markings that match targets of various heights from 0.3 m to 2.7 m at distances ranging from 100 m to 970 m. This is similar to the reticle of the 1PN51.
The light intensifier is powered by a pack of 5 D-0,55S (Russian: Д-0,55С) rechargeable cells, providing up to 7 V. The scope requires 6.25 V. The current drawn is 7 mA.
The D-0,55S battery pack is used by a range of devices including 1PN51 and 1PN51-2 and has a separate charging device. The charging device has a switch to select one of 12 V or 27 V input and two red control lamps, one to indicate that power is available and one to indicate that charging is complete.
As of 1991 the 1PN58 can be used with the following weapons (weapons on the same line share the elevation scale):