The cable is about 2cm long and wide 2mm , i not measured it but works very well. I don'k know even if it touches the contact or is only near it.

If i connect another piece of wire on the antenna the range of the bluetooth remain practically the same. Maybe to increase further the range, i need a determinate-lenght wire , for example with a online calculator the lenght of the ideal antenna results a quarter of wave of 2,450 ghz but i don't know how much is important