Radio Shack 120-2130A - Manual (Page 10)

to its owner's manual.
Connecting a Compact Disc Player
You can connect a portable CD player (or other audio component with a
line-level output) to the stereo.
Use a stereo mini-jack cable with 1/8-inch plugs. (Your local RadioShack
store offers a wide variety of mini-jack cables.)
Connect the cable to CD IN and to the output jack of the CD player or
other component.
Note: When you plug a cable into CD IN, you will not be able to listen to
the radio or a cassette tape. Be sure you disconnect the CD player
when you are not using it.