Missing screw set in the package, but the package was complete and no damage when receiving, so the logistics refused to provide any document to show the shortage, the seller showed a shipping label to declare it's right weight, Aliexpress agreed the seller's evidence, everyone please remember to take video when you open the parcel first time for the order from Aliexpress, or it's really different to help you if there is defect of the product. I'm checking with the consumer service center in UK to appeal this unfair case!
realy nice product ,robust with a exellent range of movement !