Bo2.offline.sp.mp.zm.client.v3.7z

It looks like you're working with a specific fan-made distribution or "client" for Call of Duty: Black Ops 2 (BO2). Based on the filename bo2.offline.sp.mp.zm.client.v3.7z

: Because it removes the overhead of connecting to online services, many users report slightly faster menu loading times. bo2.offline.sp.mp.zm.client.v3.7z

: Full access to Zombie maps (like Tranzit or Die Rise) without needing to connect to servers . It looks like you're working with a specific