These are 10-pin headers (with one pin missing) usually labeled F_USB1 or F_USB2 .
These pins control five critical functions of your computer case: Foxconn N15235 Front Panel Connectors - Google
: Located on Pins 1 (+) and 3 (-) . This connection is directional; if plugged in backward, the light simply won't blink during disk activity. These are 10-pin headers (with one pin missing)