in most situation,we always 250 VA  transformer for our press brake and shearing machine,in this week,one buyer wants to use 400 VA transformer,after receiving the sample,we found that the weight is beyond of our estimate.it is 5 kg per transformer.no better way,we only can afford the extra DHL charges by ourself.  in one words, a big lesson for us and we will not quote cheap DHL charges when selling press brakes parts.