1. The main body is pure copper, bearing R18810 bead bearing (pure copper product is easy to oxidize and discolor, it is a normal phenomenon)        2. After many revisions, it takes longer to rotate than the original foreign version (only for reference, rotation time is not used as hard quality indicator)       3. Wings are chamfered, non-sharp aggressive weapons, only as ordinary toys       4. Slightly shaking the finger is a normal phenomenon, not as a hard quality indicator.       5. Unless the rotation function is lost, the return will not be accepted after the receipt for more than 24 hours.       180 degree chamfer not only maintains the product's water angle, but also enhances the feel and does not have a thorny hand.