The Rolls DB25 Matchbox is a mono, passive direct box that converts an unbalanced, high-impedance 1/4 inch signal into a balanced, low-impedance xlr or microphone cable signal. It has a ground lift switch for hum elimination, and an attenuator control for padding the input signal by -20db and -40db. The pad useful if the input source is too hot, but I find that these switch only cause problems by being switch on accident, and the resulting signal is too soft. This is especially the case on live stage, where setup and take-down happens very quickly. However, on this direct box, the switch is on the top, not on the side, and it is easy to see its position from a distance. All of this makes it much easier to manage in quick setup situations.
The direct box has two parallel inputs, and this is useful if you want to run the signal to another source, such as an on-stage amplifier or powered monitor. The two inputs are not meant to be used as a mixer for two sources, although I believe I have tried it with no ill effects. Like most direct boxes with two inputs, these inputs could be mistaken for a stereo input via two 1/4 inch lines.
The sound quality is what you expect from a direct box: complete transparency with no noticeable noise, or loss of highs or lows.
I originally purchased this direct box because I saw it being used at my local church, and I've had this box for over 5 years, and it hasn't failed me once. The construction is simple and solid, and nothing feels loose or fragile inside or outside of the unit. As a simple product with a simple feature, I would recommend this direct box to anyone, for any general audio purposes.