protectoscope

protectoscope

[prə′tek·tə‚skōp]
(optics)
Device in a tank or armored car, similar to the periscope of a submarine; it enables a soldier to see around a shield without exposing himself to enemy gunfire directed at the ports of the vehicle.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.