E-11 electroscope
From Wookieepedia, the Star Wars wiki.
The BlasTech E-11 Electroscope was a zooming scope for the E-11 stormtrooper rifle. An E-11 fitted with this electroscope somehow inflicted more damage per shot fired by increasing the precision and overenergizing the bolt, but in return had a much lower rate of fire. There were two zooming modes: automatic and manual zoom. The E-11 Electroscope could also be used on other rifles.
