This is an 18k rope chain necklace, 45cm long. I purchased this item used previously. There is no box or certificate, but I had it appraised at a precious metals buyer the other day, and they confirmed it is genuine 18k gold. Length: 45cm Width: 2.0mm Weight: 2.5g (It was measured as 2.6g at the buyer, but this is the measurement at home.) Please understand that returns are not accepted to prevent switching of items. If you have any other questions, please feel free to comment.