8G ~ 10G
The SFP 10GB, or SFP+, or SFPplus is the enhanced small form-factor pluggable. It has the same shape as a 1G SFP but will support data rates up to 16 Gbit/s
XFP - transceivers for include 10 Gigabit Ethernet, 10 Gbit/s Fibre Channel, SONET at OC-192 rates, SDH at STM-64, 10 Gbit/s Optical Transport Network (OTN) OTU-2, and parallel optics links.
X2 Optics are a standardized form factor for 10 Gbps fiber optics transponders. Both 10G Ethernet and 10G Fibre Channel versions are available. X2 optics are used in datacom optical links only (not telecom), and they are smaller than XENPAK transponder