I think this is a 20 metre length of 0.4mm silver-plated copper wire from efco. Unfortunately the packaging has been lost so I'm basing the measurements on comparing it to other lengths of wire I am selling and what appears to be available from efco.
Feel free to contact me with any questions. Please take the time to look at my other listings which include other craft related items
Be aware I do not accept offers or give buy it now prices.