This very low stretch rope is made from only polyester. This, combined with the construction technique Sterling use, give the very low stretch property. The low elongation is appreciated by rope access technicians, particularly on long drops.
The feel, knotability, hardwearingness ( I am sure that is a word) make this a hugely popular rope.
This rope would fall at the top of the premium expensive rope range, but if look after it, you will gets years of service in return.