Dyneema SK-78 STS - Stronger Than Steel
STS Ocean 5000 is made of pure, pre-streched Dyneema SK78. Stronger than steel, it is extremely resistant to abrasion and UV degradation.
Heavy on the technical side...
Dynema is the Dutch company DSM Dyneema's brand of UHMWPE (Ultra High Molecular Weight PolyEthylene fiber), a long chain, high strength, oriented strand, synthetic fiber with very high strength as well as high abrasion resistance.
This fiber is also known as HMPE (High Modulus PolyEthylene).
Dyneema is available in a number of formulations, SK-60, SK-75, SK-78, SK-90, etc. Each progressively stronger and more expensive.
Honeywell International produces a similar UHMWPE fiber, marketed as Spectra