"An SFP module check is run every time an SFP module is inserted into the 8-Port Gigabit Ethernet SPA and only SFP modules that pass this check will be usable by the 8-Port Gigabit Ethernet SPA. SFP modules exist for technologies other than Gigabit Ethernet and for products other than the 8-Port Gigabit Ethernet SPA. However, the information in this document pertains only to SFP modules that plug i" . . . .