The orbital module Soyouz 7K-LOK(Лунный Орбитальный Корабль, Lunnyy Orbital'nyy Korabl')
The LOK orbital module, derived from the Soyuz, was to carry two cosmonauts to the Moon. Unlike the "terrestrial" Soyuz, it did not have solar panels to produce electricity, but it was planned to equip it with fuel cells.
The functional LOK could never be tested in space. Only a dummy ship, named Kosmos 382, was sent into Earth orbit on December 2, 1970.
For more details, pleas refer to Wikipedia.
BLOCK I engine-
Attitude engines nozzles
module for the
fuel cells (4x)