The Patriots weren't very active when free agency started on March 9, but they're making up for it big time in the trade department. For the second day in a row that Patriots have pulled off a trade that should upgrade their offense.

The Patriots have announced that they've obtained tight end Martellus Bennett and a 2016 sixth-round pick from the Bears. In exchange for Bennett and the sixth-rounder, Chicago will get a 2016 fourth-round pick from the Patriots.

Here's three things to know about the trade.

1. New England's offense is now loaded. If the Patriots' offensive line can figure out how to protect Tom Brady in 2016, the 38-year-old should be able to put up some huge numbers. Brady loves throwing to his tight ends and with the addition of Bennett, Brady almost definitely will make defenses pay if they decide to double-team Rob Gronkowski.

The last time Brady had two Pro Bowl-caliber players at tight end, he was nearly unstoppable. From 2010-12, the Patriots quarterback had both Aaron Hernandez and Gronk, and in those three years, Brady had one of the best stretches of his career, winning the NFL MVP award in 2010 and following that up with a career-high 5,235 passing yards in 2011.

In Bennett, the Patriots will be getting a tight end who made the Pro Bowl in 2014 after a season that included 916 receiving yards and six touchdowns. Bennett has finished with at least 600 receiving yards and five touchdowns in three of his past four seasons.

Besides Gronk and Bennett, Brady also has reliable weapons in Danny Amendola, Julian Edelman and running back Dion Lewis, who's expected to be 100 percent healthy once the 2016 season starts. 

2. The terms of the trade. As mentioned above, the Bears will receive New England's fourth-round pick in the 2016 NFL Draft. The Patriots won't just be getting Bennett but also receive a 2016 sixth-round pick from the Bears.

For the Bears, the move will instantly free up $5.2 million in salary cap space, which means they'll have just over $30 million in cap room once the trade's official. Getting rid of Bennett wasn't a complete shocker. According to the Chicago Sun-Times, Bears coach John Fox wasn't a huge fan after the tight end briefly held out of camp over his contract before the 2015 started.

On the Patriots' end, if Bennett's contract hasn't been restructured, that means New England will owe him $5.085 million in base salary for the 2016 season. Bennett is also in line to collect a $100,000 workout bonus.

The good news for the Patriots is if Bennett somehow struggles in New England, they can just let him walk after the 2016 season. The tight end is set to become a free agent next March.

3. Why all the trades for New England? Brady might think he'll be playing in the NFL until he's 45, but based on these recent trades, it doesn't seem like the Patriots are banking on that. Bill Belichick seems to understand that the Patriots' window of winning another title is shrinking by the year, so the Patriots coach is doing whatever possible to make sure New England wins at least one more title with Brady.

Besides the Bennett trade, the Patriots also improved their offense by adding Cardinals offensive lineman Jonathan Cooper in a trade Wednesday. That trade also gave New England another second-round for April's draft, which means the Patriots will have some serious ammo to work with come April 28.

Martellus Bennett is headed to the Patriots. (USATSI)
Martellus Bennett is reportedly headed to the Patriots. (USATSI)