The 645 is not part of the Ultra-Small class, but the dimensions are below the average and its narrow form makes it look stylish and small. It is very light, and shares the same weight as the small Nokia BH-800 which is even lighter than the Bluespoon AX2.






A stylish accessory, it is made in a combination of two colors: silver and contrasting black. Every edge in the design is rounded and the headset looks like a little barrel, being about the size of a standard AAA battery. It uses typical combination of three keys to control the functionality: a call key and a couple of volume buttons. The volume buttons are in joint rocker key and are situated on the central part of the front side – they are slightly raised but very hard to press. The calling key is in the rear part and is big and rounded - it can be easily felt, but pressing it won’t return real tactile feedback. It is surrounded by a LED ring that can blink in blue or red color, depending on the status of the headset.




Due to the keys-design and location, the headset is suitable for either ear. Its form also allows for this as attaching it to the ear is done by the earpiece only – rotating it a little is very easy and will adjust it for the one or the other ear. You have “L” and “R” indicators written on it to point you how to orientate the earpiece. It is done entirely of soft half-lucent rubber with curve that is presumed to target your ear channel for better sound experience. It can also be replaced with any of the other two coming in the box for more precise adjustment on your ear.