As you may or may not have worked out from the lack of a visible attached microphone, it's detachable. Whether this is a good thing or not rather depends on your point of view. It's good since it's not in the way when you're not using it, but bad if you need it and then can't find it. In any case it's a perfectly decent microphone and it slots securely into a mini-jack with no problems whatsoever.
Moving down a little further we find the inline volume control. This doesn't quite have the sturdy, quality feel of the headset, but it crams in plenty of functionality. With this you can control not only the overall volume of the headset, but the levels of each channel. This works in a slightly ingenious way, too. On the left edge is a rocker switch for adjusting the volume, which when pressed inward mutes the headset. This is the master control, with buttons for selecting each channel on the front face.
What's ingenious is how the volume level is communicated by means of multi-coloured backlighting. So, for example, the minimal level is green and this progresses into the different shades of blue, white and finally red at its maximum. Though it sounds somewhat convoluted, it's actually a very effective visual means of illustrating the volume level, particularly when tweaking different channels. Also on the inline control unit is the Xbox 360 headset mini-jack, with a mute switch and volume dial for the microphone also provided.
Continuing our downward path, at the end of the ample 3.6 metre headset cable are two connections: one for power and one 9-pin connection to the SCU. This 9-pin plug slots into the corresponding connection on the SCU, which has two such ports so you could connect a second headset - a nice touch, though not one many are likely to use. An analogue adapter, which breaks out into three 3.5mm jacks, ensures the set can also be used without plugging it into the SCU.
Looking more closely at the SCU, it's probably the least well designed segment of the whole set. Its plastic shell feels rather hollow and flimsy, while the assortment of buttons and switches hardly inspire confidence. As such it's probably best kept somewhere where it won't encounter too many bumps and scrapes, either on a desk or tucked safely underneath one.
Along with the two 9-pin headset connections already mentioned you'll find the optical audio input, USB-B port for PS3 headset support and three analogue audio outputs so you can connect some surround sound speakers - great for those times where discretion isn't necessary!