Listen up, Knicks fans ... there's an opportunity to own a piece of franchise history -- Dick Barnett's NBA championship ring is about to hit the auction block, just months after the legendary guard passed away.
TMZ Sports has learned Barnett's ring is from the 1970 season ... when DB, Walt Frazier, Willis Reed, Phil Jackson and the rest of the Knicks defeated the Lakers in seven games in the NBA Finals.
The item is sweet .