Mini-GBIC (Mini - Gigabit Interface Converter) optical modules complying with SFP (Small Form-factor Pluggable) agreement are popular and flexible way of optical telecommunication links, like 1000Mbit/s Ethernet, ATM, PDH/SDH as well as data communication with Fiber Channel HDDs or HDD arrays.
Modules complying with most of switches and routers with SFP socket.