Refraction shield

A refraction shield is a piece of technology from the Ladybird portion of the Generation 1 continuity family.

A refraction shield acts as a cloaking device. Covering an object in a refraction shield will render it invisible in all respects and to all detection equipment unless, and this is very important to note, the object in question is using radio transmissions to communicate with a base outside the refraction shield.

Fiction

Ladybird Books continuity

After the Decepticons built three space stations, Argon, Krypton and Xenon in Earth's orbit so they could spy on the Autobots worldwide, they used refraction shields to completely hide the stations from Autobot sensors. The refraction shields worked, but Cosmos could still detect the radio transmissions going to and from Argon. The Autobots manufactured a false signal which led to the three stations ending up on a collision course. The stations, still hidden under refraction shields, were unable to see each other, and by the time Galvatron turned off the shield, it was too late to stop them colliding. Galvatron's Air Attack