​The ​NFL free agency tampering window opened up on Monday afternoon, and the contract agreements came flowing in. While many of the top free agents were taken that day, it was Tuesday that saw some pretty solid additions as well.

No team had a better day than the Green Bay Packers, who completely revamped their defense with the signings of Za'Darius Smith, Adrian Amos, and ​Preston Smith. That alone should terrify the Chicago Bears and Minnesota Vikings.

​​Let's start with Za'Darius Smith. As a member of the Baltimore Ravens, he was a force to be reckoned with at the line of scrimmage. In fact, he was a quarterback's worst nightmare.

This past season, Smith recorded 45 tackles, 24 quarterback hits, and 8.5 sacks, which led the entire Ravens defense. Kirk Cousins and Mitchell Trubisky could be in for two rough Sundays a season with Smith entering the fray.

Green Bay wasn't done, as they signed Amos, a familiar face in the division. The former Chicago Bear isn't the flashiest player in the league by any means, but he does something that makes him stand apart form the pack, and that's force incompletions.

Last season was a career year for Amos, as he recorded 73 tackles and broke up nine passes. Now as a member of the Packers, he will look to do the same against his former team, as well as the Vikings.

Then, there's Preston Smith, who many teams thought they could get on the cheap. That wasn't the case, as the Packers swooped in on the linebacker, giving him a four-year, $52 million deal.

While you look at Smith's career statistics and see the 24.5 sacks through four years, those don't tell the whole story. Smith may not get the sexy numbers in terms of sacks, but he puts pressure on the quarterback. 

In fact, he had 32 pressures last season, which ranked higher than the likes of Myles Garrett and Melvin Ingram.

The Packers front office wanted to build a full team around quarterback Aaron Rodgers, and they did that by successfully overhauling their defense. 

Be on the lookout for the Packers next season because this defensive unit could do some serious damage in the NFC North.