PIOSK: Mini Research laboratory-2
Piosk is used as the docking port for Soyuz and Progress spacecrafts. This module also act as airlock which can be used for Extra vehicular activities.
MRM-1:Mini Research Module
MRM -1 is Russian built module with modification in storage space and additional clearance for Soyuz spacecraft. It is connected to the Zarya module. Although it was Russian built, it was launched with US space shuttle in May, 2010.
Nauka:
Multipurpose Laboratory Module
Russian laboratory module yet to be launched to ISS. It will be primary research module for Russian segment on ISS and future Russian OPSEK station.
European Robotic Arm
Russian robotic arm proposed to be launched for the Russian segment transport system.