Some sellers on Aliexpress scammer. If you want to buy products from a seller from Aliexpress, you have to pay attention to feedbacks for the product which you want to buy. If there is some bad feedback on the product or similar products, don't buy from the seller although they provide cheaper price in comparison to other seller. Be aware from the seller "Qing Feng Eletronic Co, Ltd". I have bought 30 pieces voice recorders, so 16 pieces of them don't work. I have sent several requests, but they don't respond. Aliexpress has sent two times email asking the sellet to respond me, but no response.