Ubiquiti UDC-3 UniFi Direct Attach Copper Cable, 10 Gbps, 3m

This is highly cost-effective way to connect two SFP/SFP+ devices (switches, routers, servers...) for very short distances.
They provide a low cost, low power and low latency interconnect solution for 10-Gigabit Ethernet, Fiber Channel and other industry standards, and are direct attached compliant and fully conform to the SFP+ MSA specifications.