Features: -Hot-swappable when deployed, the switch or router does not have to reboot. -Supports the "pay-as-you-populate" model. -Interchangeable with other 100BASE-X SFPs on the same line card. -Supports the Cisco quality ID feature that enables the switch or router to identify whether or not the SFP is a Cisco qualified SFP. -Optically interoperable with respective 100BASE-X Ethernet interfaces on the same link. The Cisco 100BASE-EX SFP (part number GLC-FE-100EX) operates on ordinary single-mode fiber-optic (SMF) link spans up to 40 kilometers long.