The Simon Systems CB4 is a four channel headphone distribution box that is for use in the studio. It's a really simple box as there isn't much at all to setting it up and using it. A studio that I used to work at had one of these for splitting headphone signal, and it's really a top notch splitter. It's got a really sturdy build and is a box that should really last a lifetime if treated properly. The box has got an XLR input and output and four 1/4" jacks for plugging in your headphones. Each of the four channels has it's own volume knob for setting your headphone level on each individual set of headphones, and it also has a switch so you can either monitor the stereo signal or just the left or right if you so desire. You can daisy chain two or more of these together as well if you need more channels, which is a nice feature if you're in a larger studio or if you using this in any situation where you would need more than four channels. I don't know what kind of price the Simon Systems CB4 commands, but it's got a really incredible build so I don't think it's too cheap. Having said that, if you foresee yourself needing something like this for a while to come in the studio or elsewhere, it's definitely a good investment since you know it will last. Everyone I've spoken to about the CB4 really seems to love it as they only have good things to say about it, and from my first hand experience I have to agree. It seems like the CB4 is almost becoming an industry standard due to it's great make up and ease of use. If you need a great headphone box, look no further than the Simon Systems CB4!