Rangefinder
From Wookieepedia, the Star Wars wiki.
A rangefinder was a device that zoomed in on distant objects and provided the user with a dynamic visual data readout based on the item being observed. Most models displayed basic information, such as range, size, speed, or species, but some more advanced versions provided advanced functionality that allowed the user to lock onto a target and track it even through walls.
Rangefinders were commonly built into electrobinoculars, but they were also frequently integrated into combat helmets, as well as mounted on blaster sights. Numerous military factions made use of rangefinder technology to help them on the battlefield, including the Trandoshan Mercenary Group and the Grand Army of the Republic.
