Quick answer: This is a pair of fins from Mares.
For bigger divers, fin fit starts with the foot pocket. Size to the boot or bare foot you'll actually use, and look for a blade that matches your kick so you save air and energy.
Offered in 4 options, including Mares Avanti Super-Channel Open Heel Fins with Bungee Strap Regular White/Aqua, Mares Avanti Super-Channel Open Heel Fins with Bungee Strap X-Large Black, Mares Avanti Super-Channel Open Heel Fins with Bungee Strap Small Black, Mares Avanti Super-Channel Open Heel Fins with Bungee Strap X-Large White/Aqua.
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 Wide Feet & Larger Divers.