The Cisco Catalyst 3750-X Series and 3560-X Series Switches support an optional network module for uplink ports. The default switch configuration doesn't include the uplink module, so you have the flexibility to choose from a four GbE port (3KX-NM-1G) or a two 10GbE port (3KX-NM-10G) network module.
This 10GbE uplink module features four physical ports with two SFP+ and two regular SFP ports. The SFP+ interface supports both 10GbE and GbE port, allowing you to use your investment in GbE SFP and upgrade to 10GbE when business demands change, without having to do a comprehensive upgrade of the access switch. The uplink module is hot swappable.