You will receive 4 wireless Infrared Fold Flat headphones. Enjoy music, movies and more! Smaller Size: Great for Children and Adults, headband adjusts to fit large and small headsizes. Automotive Grade IR Headphones: Will work on any vehicle that uses infrared headphones. No programming required! Simply turn on the headphones and they will connect to your vehicles rear entertainment system. IR Sensors: Uses infrared light to assure great sounding clear reception. Sound control: equipped with it's own volume control to suit your listening needs. Automatic Shut Off: Headphones will automatically shut off after 3 minutes when no audio is detected to ensure maximum battery life. Fold Flat & Collapsible Design: Headphones fold flat and again toward the headband for extra compact storage. Comfortable Fit: Soft padded ear pieces and padded adjustable headband ensures a comfortable fit for hours of enjoyment. Two Channel: Will do everything a one channel headphone does but gives you the option to change between two different audio sources. For example, if you have two LCD screens in your vehicle and you want passengers to be able to watch two different shows, you will need a two channel headphone. Batteries: Requires two AAA batteries. On-Off Buttons: Each unit has it's own On-Off button with a power on indicating light. Operating Instructions: Battery Installation: Squeeze the edges of the left "Melodeez" cover (opposite side of controls) and turn counter clockwise. Power on: Hold the center button for 1-2 seconds until the power light comes on. Switching from Channel "A" to Channel "B": Once the unit is "ON" a red light will indicate channel "A". Press again, and the light will turn Green for Channel "B".