The NAGRA IS was designed as a more compact and simpler alternative to the larger NAGRA models – ideal for journalists without technical training. That’s why some interpreted its IS designation as a nickname: “Idioten Sicher” – meaning “idiot-proof.”
Its truly rugged construction is evident in the fact that it had three motors for precise tape transport – separate ones for the capstan, take-up, and supply reels. It also featured a large modulometer for accurate signal level measurement and switchable high-pass and low-frequency filters. The robust metal casing has side “ears” – that is, mounts for connecting microphones and headphones.
Although the NAGRA IS was intended as a straightforward device for journalists, it was also favored by certain intelligence services – precisely because of its inconspicuous nature and reliability.