A part of the review has been auto-translated.
Very fast shipment and good quality. Many friends here have complained about the manual which is in Chinese. So I tried to translate the manual using online translation. Please check the photos. If it is not very clear, just take a screenshot and then zoom in to see better. Sorry for the low quality, but that's the best possible. Hope it is helpful
tested quickly on an AA battery, it worked. in reality the device send the current every 1.5 seconds with a beep, so it does not detect if you have contact or not (i have the mini usb version). but for the price it's cool. only 2 drawbacks are on the solder pins: it seems they are not removable and they are not isolated on a long distance, the distance where you hold it with your fingers... i'm not sure what happens if your fingers are wet... i isolate them with some thermalshrink tubes for safety.