Cisco SFP+ Copper Twinax cables are suitable for very short distances. Direct attach cable - SFP+ to SFP+ - 2 m - twinaxial -for 250 Series; Catalyst 2960, 2960G, 2960S, ESS9300; Nexus 93180, 9336, 9372; UCS 6140, C4200.
eBay