Features: 1.Pls check IR sensor frequencies of your car DVD players and make sure they are universal before purchasing. (consult your DVD's manual or manufacturer. Universal IR frequencies: Channel A: L/2.3MHZ,R/2.8MHZ; Channel B: L/3.2MHZ,R/3.8MHZ). If you DVDs are non-universal, it will cause no sound, audio cuts, only hear at one side.2.The Simolio IR wireless headphones can also be used outside the car with the included Aux cable for smart phones, Tablets, MP3 etc, or equipped with an IR transmitter for watching TV at home.3.Pls pay attention to the IR transmitting angle and distance. Sound will be cracking if too far away, or not in sight of IR transmitter, which is limitation of the IR system type, not the product itself. The best audio signal will be obtained if you sit directly in front of the monitor within 6 feet.4.There are 2 channels option for the Simolio IR headphones. Set each DVD on a different channel, and the headphone to the channel of the DVD you would like to listen to.5.The headband incorporates memory elastic stainless steel strips inside, you can remould the headband shape to fit you better,or adjust the wearing angle to make the headphones fit snug on your ears. Features: 1. This Bluetooth receiver 3.5mm allows you to wirelessly stream high fidelity audio from any Bluetooth-enabled devices including smartphones, tablets, computers, laptops etc. to your car stereo system, home stereo, vintage speaker via 3.5mm AUX cable (or 3.5mm male to male connector). 2. The working range of this car Bluetooth adapter is 50-70FT (15-20M) indoors and 100FT (30M) line-of-sight outdoor environment. 3. Volume control buttons allows easy volume and track adjustments. 4. Easy to use Bluetooth car adapter. Simply power on the receiver, plug the receiver to your car audio system, and pair the receiver to any of your Bluetooth capable device, including smart phones, laptop, Bluetooth-enabled PC, etc..