[slipcovers]

Originally Posted by Average Guy

According to Mike Florio from NBC Sports, "as to the fact that the officials didn’t notice anything wrong with the balls while handling them after every play, the [league] source explains that a pressure difference of one or two pounds would not be obvious, if the official is not specifically looking for it."

Source: Footballs were properly checked before Colts-Patriots game | ProFootballTalk

According to a news reporter, 2# of air weights about the same as a standard white business envelope, that he held in his hand.