1PN51-2 (Russian: 1ПН51-2) is the GRAU index for a Soviet designed passive night scope for the RPG-29 rocket launcher.
1PN is the GRAU index of night vision devices, where PN stands for Nochnoy Pritsel (Russian: Ночной прицел) meaning night sight.
It is thus more compact than the similar multi-model 1PN51 night vision scope.
It is attached onto a matching side rail on the RPG after which a lever on the scope is pressed to hold it in place.
The reticle has markings that match the height of a typical armoured vehicle at ranges 200 m, 300 m, 400 m and 500 m. 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 V ± 1 V. The maximum current drawn is 40 mA.