SFP+ is the 10G fiber optic transceiver used for 10G Ethernet and other high speed transmissions in order to meet increasing BW demands. SFP+ interconnects are designed to support 8 Gbps Fibre Channel, 10 Gbps Ethernet and Optical Transport Network.
SFP+ modules are exactly the same dimensions as regular SFPs. Connectors, cable assemblies, light-pipe cover assemblies and sealed optical assemblies are also same for both SFP+ and SFP. Note that for most vendors, it is possible to fit an SFP module into an SFP+ slot but not vice versa.
