BCY’s DynaFlight ‘97 is the strongest single fiber bowstring on the market. It has proven to have very high abrasion resistance and low creep and stretch. Now BCY technicians have reformulated the same basic fiber structure and created a revolutionary new bowstring material: Formula 8125. This material has the same strength as DynaFlight ‘97, but the smaller diameter strand means it is faster. Shooters can use a higher number of strands, offering more flexibility and, of course, greater speed. 4 oz. spool.