The DS-101A uses a 3.5mm audio jack known as a TRS (Tip, Ring and Sleeve) connector. This type of connector is used almost universally for portable equipment such as media / music players, portable CD and DVD players, radios etc. It is also common on multi-media mobile phones to allow users to plug in legacy headphones to listen to their music.Whilst the 3.5mm audio connector is a standard, there are some differences in configuration that can cause compatibility issues between different devices. Typically these relate to the number of Rings (or poles) and what these poles are used for.