As with most headsets, Bluetrek has kept the controls to a minimum. There's a large multifunction button positioned on the outside while the up and down volume controls sit on the top and bottom edges of the device. This small number of controls, however, does mean that there's a lot of doubling up of functions and as a result you'll have to check out the manual to discover how all of them are accessed. Only the quick start guide is included in the box, so you have to pay a trip to the Bluetrek website to download the PDF of the full manual.
Nevertheless, the majority of the controls are pretty straightforward. You tap once on the call button to answer or drop a call, press and hold the button for two seconds to reject a call and press and hold it for three seconds to redial the last called number. As well as being used for adjusting volume, the volume-up button also doubles as a mute control. To activate mute you just press and hold it for three seconds and to cancel it you tap it again once.
Pairing the X3 with your phone is a very simple affair as the headset enters pairing mode when you press and hold the call button for seven seconds. The headset's LED will then flash blue and red to show you it's in pairing mode. After that it's just a matter of performing a device search on your phone and entering ‘0000' as the passcode to get the phone and headset paired with each other.
In use the X3 can certainly take some abuse. Despite chucking it about a bit and subjecting it to considerable dust and moisture it never complained. However, it's important to bear in mind that it's splash-proof rather than waterproof, so you shouldn't go dropping it in your coffee cup.