Rob Gronkowski: I'll Get You Jacked ... With My New Gym Equipment Line

Rob Gronkowski wants to be the Tom Brady of gym equipment -- THE KING -- and now he's launched his own line of fitness products to take you to Jacked City.

The entire Gronk family is involved in Gronk Fitness ... selling everything from push sleds to battle ropes, squat racks and more.

Turns out, Gronk's dad used to own fitness retails stores and spent 25 years in the business -- and since his kids are bona fide muscle heads, they decided to put together their own gym equipment company.

We spoke with Rob's brother, Dan Gronkowski, who says the idea came about last year -- "We said if Rob wins the Super Bowl, we'll do it. And he did. So we did."

Dan says all the stuff is commercial grade quality -- "This isn't us slapping our names on some crappy product, this is quality stuff."

And the family is dead serious about growing the business -- "We want to be the place to go to for athletes and gyms."