PU is a Soviet optical sight, originally created in 1940, for use together with a sniper version of the Tokarev self-loading rifle (SVT-40).

The design turned out to be so successful and in demand that the production was not stopped even after the war. Until now, copies of this sight are in steady demand in Russia and abroad. Various options are produced, for example - at the Novosibirsk Instrument-Making Plant under the designation "universal sight PU 3.5x22 for the Mosin rifle."
The design of the sight had a significant impact on many foreign developments, for example, the German optical sight Gw ZF4.