WS-C3750X-12S-S

Cisco Catalyst 3750-X Series Switch

Stackable 12 GE SFP ports

Four optional uplink network modules with GE or 10GE ports

Dual redundant, modular power supplies and fans

Media Access Control Security (MACsec) hardware-based encryption

Flexible NetFlow and switch-to-switch hardware encryption with the Service Module uplink

USB Type-A and Type-B ports for storage and console respectively and an out-of-band Ethernet management port

StackWise Plus

Cisco StackPower^TM technology: An innovative feature and industry first for sharing power among stack members

Cisco StackWise Plus technology for ease of use and resiliency with 64 Gbps of throughput

Investmentprotection with backward compatibility with all other models of Cisco Catalyst 3750 Series Switches

                                                                                                     Figure 1

Cisco Catalyst 3750-X Series Switches support 4 optional network modules for uplink ports (Figure 1);
The default switch configuration doesn’t include the uplink module; 
When purchasing switch, customers have flexibility to choose any group of network modules described below:

                                                                                              Figure 2

Dual Redundant Modular Power Supplies

Cisco Catalyst 3750-X Series and 3560-X Series Switches support dual redundant power supplies (Figure 2);
One power supply is shipped with the switch by default;
Other power supply/suppliers can be purchased when ordering the switch or next time according to your needs.
If only one power supply is installed, it should always be in the power supply bay 1.

Table below shows the different power supplies available in these switches and available PoE power.

Power Supply Models

Cisco Catalyst 3750-X Series Switch WS-C3750X-12S-S is an enterprise-class lines of stackable and standalone switches, respectively. Catalyst 3750-X switches provide high availability, scalability, security, energy efficiency, and ease of operation with innovative features such as Cisco StackPower, IEEE 802.3at Power over Ethernet Plus (PoE+) configurations, optional network modules, redundant power supplies, and Media Access Control Security (MACsec) features. Cisco Catalyst 3750-X Series with StackWise Plus technology provides scalability, ease of management and investment protection for the evolving business needs. The Cisco Catalyst 3750-X switches enhance productivity by enabling applications such as IP telephony, wireless, and video for borderless network experience.