By now, Cole Eiserman and Kamil Bednarik have spent countless hours together.

They’ve been teammates, linemates, classmates, roommates and Islanders draftmates — all in a three-year stretch with the U.S. National Team Development Program and Boston University.

They’re also close friends who know each other well enough to admit the following with confidence: They couldn’t be more different.

“He’s a quieter kid,” Eiserman told The Post at Islanders rookie camp in early July, which both prospects attended. “I’m probably the more ‘like to be around the guys,’ upbeat guy.”