The downlink ports on the N9348Y12C-SE1 switch.
The Cisco Nexus N9348Y12C-SE1 switch has 48 downlink ports that connect to servers. Each of these ports supports 1-Gigabit, 10-Gigabit, and 25-Gigabit and 50-Gigabit (bottom 16 ports) speeds using SFP+ transceivers.
For a listing of the transceivers and cables that the optical downlink ports support, see https://www.cisco.com/c/en/us/support/interfaces-modules/transceiver-modules/products-device-support-tables-list.html