Lenovo ThinkCentre M910s User Manual And Hardware Maintenance Manual page 4

Overview
USB 3.0 connectors (2)
9
Used to connect a USB-compatible device. For optimal data
transfer, connect a USB 3.0 device to a USB 3.0 connector instead
of a USB 2.0 connector.
USB 3.0 connectors (2)
10
Used to connect a USB-compatible device. For optimal data
transfer, connect a USB 3.0 device to a USB 3.0 connector instead
of a USB 2.0 connector.
Illuminated red dot
11
This indicator is on when the computer is on.
Internal speaker (optional)
12
Used to listen to the sounds from your computer without using a
headset or headphones.
4