C3650-STACK-KIT= is a Cisco Catalyst 3650 Stack Module Spare. It includes a StackWise Adapter and a StackWise Cable.
The Cisco Catalyst 3650 supports an optional stacking module that is based on the Cisco StackWise-160 technology. StackWise-160 has a stack bandwidth of 160 Gbps. It creates a highly resilient single unified system of up to 9 switches. It also enables local switching in Cisco Catalyst 3650 Series Switches.