Amazon.com : PetAmi Deluxe Pet Carrier Backpack for Small Cats and Dogs, Puppies | Ventilated Design, Two-Sided Entry, Safety Features and Cushion Back Support | for Travel, Hiking, Outdoor Use (Heather Gray) :
Superdry Bomber Montana Backpack Blue | Dressinn
These dual slots on many bags, most notably superdry. I doubt its design because its on so many different brands : r/whatisthisthing
Amazon.com : PetAmi Deluxe Pet Carrier Backpack for Small Cats and Dogs, Puppies | Ventilated Design, Two-Sided Entry, Safety Features and Cushion Back Support | for Travel, Hiking, Outdoor Use (Black) :