For most of our shipping channel,the logsitc company charged us by size weight/volume weight.Normal formular is as follows ( Length (cm)Xwidth (cm)Xheight (cm)/ 5000 = volume weight in kg)
For example, the box size of the our Package box of X9DP is 31cm*32cm*17cm,the volume weight
is 3.3kg (31*32*17/5000).Since our package box have some space, if you add 5 more receivers, the
shipping cost will still be the same.
So we strongly recommend you to order some small items togher with the radio to save some shipping cost.