Quick answer: This is a pair of fins from Cressi. It's offered in men's US 13 and up, which puts it in our fins for big feet.
Most fin pockets stop well short of a men's 13, which leaves a lot of big-footed divers squeezing into the largest size available. A pocket that actually fits turns every kick into propulsion instead of pain, and it leaves room for a dive boot when you need one.
Offered in 4 options, including 9/10 Black, 12/13 Blue, 11/11.5 Black, 12/13 Black.
Size to the boot you'll wear, not your street shoe. Wide or high-volume feet should lean toward the larger size, and open-heel fins give you the most room to adjust. Read How to Choose Scuba Fins for Comfort and Power. More options: Fins for Big Feet (Men's 13 and Up).