Lexar Multi-Card 24-in-1 USB Reader - Manual (Page 7)

LED Activity Light
the Led activity light was specifically designed to safeguard the files stored on
your memory card, preventing interrupted file transfer, and reducing the risk
of data loss or card damage. the light acts as a status indicator to help ensure
proper use of the reader.
LED Indicators:
LED off: the reader is plugged into the computer but does not have a
card inserted.
LED on: the reader is plugged into the computer with card(s) inside the reader
LED blinks continuously: the reader is transferring data between memory cards
in different slots, or memory card and computer. Once the Led stops blinking,
the data transfer is complete.