Negator Packs are devices made by Tony Stark.
The Negator Packs were designed specifically to disable armored suits similar to Iron Man's. After the Ghost stole his armor specs and sold them to Obadiah Stane and Justin Hammer, he built the Negator Packs to help him stop the suits that were going to be used against him.
The Packs disable the armor and damage them beyond repair, but the pilot will remain perfectly fine. The Packs can be countered if someone knows what they are made of.