Russian 125mm Svir / Reflekts anti-tank missile standoff launch spring

Russian 125mm launch spring belonging to a 9K120 Svir or 9K119 Refleks GL-ATGM (Gun-Launched Anti Tank Guided Missile) fired from 125mm main guns on Russian tanks. 
 

The section seen here is attached to the 125mm aft cap of the cartridge and loaded in behind the missile. When fired the part seen here helps to gently launch the missile before its rocket motor is ignited and is ejected out the end of the barrel to fall to the ground. It contained no dangerous substances and allowed guidance connection to be made. 
 

Happy to provide further photos of these in use however I cannot post them here. Open to offers, buyer pays shipping.