C3KX-NM-10G Network Modules Catalyst 3560-X, 3750-X Series C3KX-NM-10G module fits Cisco Catalyst 3650-X and 3750-X switches, so you can just upgrade modules instead of replacing them when you need higher transmission speeds. Besides, it’s easy to be configured so that network designers can mix and match the type of transceivers with their own port module preferences.