The Porta-Communicator was an accessory for the Steve Austin doll manufactured by Kenner in 1976.
It was a toy that came in two parts. One was a backpack that could be strapped to Steve's back. The other was a microphone connected to the backpack by a wire. When the user spoke into the microphone, a speaker concealed in the backpack would amplify the user's voice. Thus, users could somewhat simulate the effect of talking to Steve remotely.
The packaging on the product was somewhat misleading in that it claimed the device could "transmit" the user's voice to the backpack, and said there was "no limit to the exciting adeventures you can create" with the device. The "limit", however, was the length of the wire that connected the two parts of the toy. Though it did say that there was a "10 foot cord included", the packaging seemed to imply wireless communication, as with a walkie-talkie.
The toy was also promoted at the end of "The Effigy", a story in Issue #2 of the Six Million Dollar Man comic book from Charlton Comics, featuring Austin breaking the fourth wall and talking about the Steve Austin action figure (which featured prominently in the story), the Porta-Communicator (referred to as a "backpack radio") and the Bionic Transport and Repair Station playset.