The Rolls MX41b is a utility mixer designed to expand the input capability of a constrained physical device. With this mixer, you can route up to four stereo inputs into one stereo output. On one side of the mix, you'll find 1/4" phone and 3.5mm mini inputs with 100-kOhm level fader controls. The rear features a stereo 1/4" TRS output, as well as a stereo 3.5mm output.