my dear customer, before sending the samples, we agreed on the freight cost, then send the samples. We donot earn your any freight cost, I said if you think freight high, we can send toany places in China for free and then you arrange by yourlselves. The courier charge so much ,we have no choice. besides, this 50 pcs of samples are totally free. About the lighter quality, during our conversation, you said 5 pcs have leakage, but here why you say more than half?? I donot know if you did refill them properly. when we do bulk goods, we also refill from the bottom, it will have around 0.5% have problems and we will take them out to make sure the bulk goods all will be good ones. But due to courier cannot send goods with gas, so we send without gas, but you know for some customers, after finishing the gas, they won't fill the gas again. For this rate, it meets the international stardard.

dear, first, you said the goods will be finally sent to Bolivia, not USA, and before sending the samples, I told you which test we can pass. Second, samples are free, we donot charge you anything, the money is just for the DHL freight.