This is 4 ply wool sock knitting yarn by Dee Hardwicke from the Regia Garden City Color range. This is shade #3852, Delphinium. It is a mix of silver grey, blues and greens and will knit up like the sock in the right hand photo.
The yarn is 75% wool and 25% polyamid and is very soft . It is machine washable and does not felt and is color fast.
It knits on 2.5mm / 3mm needles at 30 stitches over 42 rows for a 4" square.Each ball is 420 meters in length and you will need 1 ball for one adult pair of socks.