Asus Motherboard A8N-SLI Premium - Manual (Page 173)

ASUS A8N-SLI Premium 6-5
5. Align and insert the SLI flexible cable connector to the goldfingers on
each graphics card. Make sure that the connector is firmly in place.
6. If using a 20-pin ATX power connector, connect a 4-pin ATX power
cable to the EZ Plug™ labeled EZ_PLUG on your motherboard.
The onboard red warning LED lights up if you do not plug a 4-pin ATX
power cable to the EZ Plug.
SLI flexible cable connector
ASUS EZ Plug™