From the Bog Dog team:
The game-changing comfort you love just got even better. This second generation features even more cushioning for a seriously plush and comfortable ride. The upgraded, resilient ZipFoam™ midsole delivers an even softer, lighter, and more energetic underfoot experience. Up top, the recycled engineered mesh provides a secure, well-ventilated fit. On the bottom, a new outsole design features strategic rubber zones to enhance flexibility and increase traction. Max your miles, your stride, and your flow with Atmos 2—delivering comfort that lasts and cushioning that keeps up.