Aux cables or auxiliary wires are portable wires that consist of a 3.5mm jack on both of its ends. Their unique properties enable you to connect your smartphone to an amplifier, like a home theatre, car stereo, external speakers, and more. By the way, you can use the aux cables in cars too, for listening to music. Most people prefer these cables longer so that they can reach the back seat. In this case, you can use a connector to connect two cables together. Otherwise, you will only find a standard size of aux cables in the market.