The ring Kevin Hart gifted to Tom Brady for being such a good sport during Sunday night's roast wasn't merely a prop ... TMZ Sports has learned it's the real deal -- coming in with a staggering worth of $40,000!!!
We're told celeb jeweler Jason Arashaben, CEO of Jason of Beverly Hills -- who actually created TB12's final Tampa Bay Buccaneers Super Bowl ring -- was the mastermind behind the piece, tasked with completing it in time for Netflix's "The Greatest Roast of All Time: Tom Brady."
Jason threw the kitchen sink at the bling ... loading it with just under 400 diamonds, rubies and sapphires. A spokesperson for the jeweler tells us it's all set on yellow gold, weighs around 6 carats -- and would cost normies about as much as a brand-new car to own.
Brady was clearly thrilled with how it all came out ... check out his reaction when Hart handed it off to him, he rocked it proudly with a huge grin.
"I'm honored to have made Tom Brady's last two championship rings," said Jason. "First with the Tampa Bay Buccaneers and now for the 'GROAT' special."
No word yet if Brady has plans to house it with his other championship rings ... but it wouldn't shock anyone if he did -- considering, you know, all the jabs he had to eat in order to get it!